I forgot to mention I also ran the M5Burner as admin which may have changed something. Originally when I would download UIFlow it would instantly say retry, but a restart of the burner would show that it installed. Maybe running as admin allowed it to download fully instead. Which is why it was originally only a partial install.

I tried that about a 20 times yesterday. Today 1.7.1.1 became available and that worked like it was supposed to. Not sure what the issue was or what changed (other than the version) but here's the output. Thanks for your help!
.
.
.

=================
Start Burn
=================
--chip esp32 --port COM9 --baud 1500000 --before default_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size detect 0x7ff000 C:\Users\A323841\Desktop\M5Burner\packages\fw\other\wifi.bin 0x1000 C:\Users\A323841\Desktop\M5Burner\packages\fw\core\UIFlow_Core2-v1.7.1.1-core2.bin
=================
esptool.py v2.5.0
Serial port COM9
Connecting...
.
.

Chip is ESP32D0WDQ6 (revision 1)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse
MAC: b8:f0:09:c4:7b:d0
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 1500000
Changed.
Configuring flash size...
Auto-detected Flash size: 16MB
Compressed 100 bytes to 37...

Writing at 0x007ff000... (100 %)

Wrote 100 bytes (37 compressed) at 0x007ff000 in 0.0 seconds (effective 200.5 kbit/s)...
Hash of data verified.
Compressed 8376320 bytes to 3457017...

Writing at 0x00001000... (0 %)

Writing at 0x00005000... (0 %)

Writing at 0x00009000... (1 %)

Writing at 0x0000d000... (1 %)

Writing at 0x00011000... (2 %)

Writing at 0x00015000... (2 %)

Writing at 0x00019000... (3 %)

Writing at 0x0001d000... (3 %)

Writing at 0x00021000... (4 %)

Writing at 0x00025000... (4 %)

Writing at 0x00029000... (5 %)

Writing at 0x0002d000... (5 %)

Writing at 0x00031000... (6 %)

Writing at 0x00035000... (6 %)

Writing at 0x00039000... (7 %)

Writing at 0x0003d000... (7 %)

Writing at 0x00041000... (8 %)

Writing at 0x00045000... (8 %)

Writing at 0x00049000... (9 %)

Writing at 0x0004d000... (9 %)

Writing at 0x00051000... (9 %)

Writing at 0x00055000... (10 %)

Writing at 0x00059000... (10 %)

Writing at 0x0005d000... (11 %)

Writing at 0x00061000... (11 %)

Writing at 0x00065000... (12 %)

Writing at 0x00069000... (12 %)

Writing at 0x0006d000... (13 %)

Writing at 0x00071000... (13 %)

Writing at 0x00075000... (14 %)

Writing at 0x00079000... (14 %)

Writing at 0x0007d000... (15 %)

Writing at 0x00081000... (15 %)

Writing at 0x00085000... (16 %)

Writing at 0x00089000... (16 %)

Writing at 0x0008d000... (17 %)

Writing at 0x00091000... (17 %)

Writing at 0x00095000... (18 %)

Writing at 0x00099000... (18 %)

Writing at 0x0009d000... (18 %)

Writing at 0x000a1000... (19 %)

Writing at 0x000a5000... (19 %)

Writing at 0x000a9000... (20 %)

Writing at 0x000ad000... (20 %)

Writing at 0x000b1000... (21 %)

Writing at 0x000b5000... (21 %)

Writing at 0x000b9000... (22 %)

Writing at 0x000bd000... (22 %)

Writing at 0x000c1000... (23 %)

Writing at 0x000c5000... (23 %)

Writing at 0x000c9000... (24 %)

Writing at 0x000cd000... (24 %)

Writing at 0x000d1000... (25 %)

Writing at 0x000d5000... (25 %)

Writing at 0x000d9000... (26 %)

Writing at 0x000dd000... (26 %)

Writing at 0x000e1000... (27 %)

Writing at 0x000e5000... (27 %)

Writing at 0x000e9000... (27 %)

Writing at 0x000ed000... (28 %)

Writing at 0x000f1000... (28 %)

Writing at 0x000f5000... (29 %)

Writing at 0x000f9000... (29 %)

Writing at 0x000fd000... (30 %)

Writing at 0x00101000... (30 %)

Writing at 0x00105000... (31 %)

Writing at 0x00109000... (31 %)

Writing at 0x0010d000... (32 %)

Writing at 0x00111000... (32 %)

Writing at 0x00115000... (33 %)

Writing at 0x00119000... (33 %)

Writing at 0x0011d000... (34 %)

Writing at 0x00121000... (34 %)

Writing at 0x00125000... (35 %)

Writing at 0x00129000... (35 %)

Writing at 0x0012d000... (36 %)

Writing at 0x00131000... (36 %)

Writing at 0x00135000... (36 %)

Writing at 0x00139000... (37 %)

Writing at 0x0013d000... (37 %)

Writing at 0x00141000... (38 %)

Writing at 0x00145000... (38 %)

Writing at 0x00149000... (39 %)

Writing at 0x0014d000... (39 %)

Writing at 0x00151000... (40 %)

Writing at 0x00155000... (40 %)

Writing at 0x00159000... (41 %)

Writing at 0x0015d000... (41 %)

Writing at 0x00161000... (42 %)

Writing at 0x00165000... (42 %)

Writing at 0x00169000... (43 %)

Writing at 0x0016d000... (43 %)

Writing at 0x00171000... (44 %)

Writing at 0x00175000... (44 %)

Writing at 0x00179000... (45 %)

Writing at 0x0017d000... (45 %)

Writing at 0x00181000... (45 %)

Writing at 0x00185000... (46 %)

Writing at 0x00189000... (46 %)

Writing at 0x0018d000... (47 %)

Writing at 0x00191000... (47 %)

Writing at 0x00195000... (48 %)

Writing at 0x00199000... (48 %)

Writing at 0x0019d000... (49 %)

Writing at 0x001a1000... (49 %)

Writing at 0x001a5000... (50 %)

Writing at 0x001a9000... (50 %)

Writing at 0x001ad000... (51 %)

Writing at 0x001b1000... (51 %)

Writing at 0x001b5000... (52 %)

Writing at 0x001b9000... (52 %)

Writing at 0x001bd000... (53 %)

Writing at 0x001c1000... (53 %)

Writing at 0x001c5000... (54 %)

Writing at 0x001c9000... (54 %)

Writing at 0x001cd000... (54 %)

Writing at 0x001d1000... (55 %)

Writing at 0x001d5000... (55 %)

Writing at 0x001d9000... (56 %)

Writing at 0x001dd000... (56 %)

Writing at 0x001e1000... (57 %)

Writing at 0x001e5000... (57 %)

Writing at 0x001e9000... (58 %)

Writing at 0x001ed000... (58 %)

Writing at 0x001f1000... (59 %)

Writing at 0x001f5000... (59 %)

Writing at 0x001f9000... (60 %)

Writing at 0x001fd000... (60 %)

Writing at 0x00201000... (61 %)

Writing at 0x00205000... (61 %)

Writing at 0x00209000... (62 %)

Writing at 0x0020d000... (62 %)

Writing at 0x00211000... (63 %)

Writing at 0x00215000... (63 %)

Writing at 0x00219000... (63 %)

Writing at 0x0021d000... (64 %)

Writing at 0x00221000... (64 %)

Writing at 0x00225000... (65 %)

Writing at 0x00229000... (65 %)

Writing at 0x0022d000... (66 %)

Writing at 0x00231000... (66 %)

Writing at 0x00235000... (67 %)

Writing at 0x00239000... (67 %)

Writing at 0x0023d000... (68 %)

Writing at 0x00241000... (68 %)

Writing at 0x00245000... (69 %)

Writing at 0x00249000... (69 %)

Writing at 0x0024d000... (70 %)

Writing at 0x00251000... (70 %)

Writing at 0x00255000... (71 %)

Writing at 0x00259000... (71 %)

Writing at 0x0025d000... (72 %)

Writing at 0x00261000... (72 %)

Writing at 0x00265000... (72 %)

Writing at 0x00269000... (73 %)

Writing at 0x0026d000... (73 %)

Writing at 0x00271000... (74 %)

Writing at 0x00275000... (74 %)

Writing at 0x00279000... (75 %)

Writing at 0x0027d000... (75 %)

Writing at 0x00281000... (76 %)

Writing at 0x00285000... (76 %)

Writing at 0x00289000... (77 %)

Writing at 0x0028d000... (77 %)

Writing at 0x00291000... (78 %)

Writing at 0x00295000... (78 %)

Writing at 0x00299000... (79 %)

Writing at 0x0029d000... (79 %)

Writing at 0x002a1000... (80 %)

Writing at 0x002a5000... (80 %)

Writing at 0x002a9000... (81 %)

Writing at 0x002ad000... (81 %)

Writing at 0x002b1000... (81 %)

Writing at 0x002b5000... (82 %)

Writing at 0x002b9000... (82 %)

Writing at 0x002bd000... (83 %)

Writing at 0x002c1000... (83 %)

Writing at 0x002c5000... (84 %)

Writing at 0x002c9000... (84 %)

Writing at 0x002cd000... (85 %)

Writing at 0x002d1000... (85 %)

Writing at 0x002d5000... (86 %)

Writing at 0x002d9000... (86 %)

Writing at 0x002dd000... (87 %)

Writing at 0x002e1000... (87 %)

Writing at 0x002e5000... (88 %)

Writing at 0x002e9000... (88 %)

Writing at 0x002ed000... (89 %)

Writing at 0x002f1000... (89 %)

Writing at 0x002f5000... (90 %)

Writing at 0x002f9000... (90 %)

Writing at 0x002fd000... (90 %)

Writing at 0x00301000... (91 %)

Writing at 0x00305000... (91 %)

Writing at 0x00309000... (92 %)

Writing at 0x0030d000... (92 %)

Writing at 0x00311000... (93 %)

Writing at 0x00315000... (93 %)

Writing at 0x00319000... (94 %)

Writing at 0x0031d000... (94 %)

Writing at 0x00321000... (95 %)

Writing at 0x00325000... (95 %)

Writing at 0x00329000... (96 %)

Writing at 0x0032d000... (96 %)

Writing at 0x00331000... (97 %)

Writing at 0x00335000... (97 %)

Writing at 0x00339000... (98 %)

Writing at 0x0033d000... (98 %)

Writing at 0x00341000... (99 %)

Writing at 0x00345000... (99 %)

Writing at 0x00349000... (100 %)

Wrote 8376320 bytes (3457017 compressed) at 0x00001000 in 51.0 seconds (effective 1313.5 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting via RTS pin...
=================
Burn Successfully
=================

Console output:
=================
Start Burn
=================
--chip esp32 --port COM9 --baud 1500000 --before default_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size detect 0x1000 C:\Users\A323841\Downloads\M5Burner\packages\fw\core\UIFlow_Core2-v1.7.1-core2.bin
=================
esptool.py v2.5.0
Serial port COM9
Connecting...
.

Chip is ESP32D0WDQ6 (revision 1)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse
MAC: b8:f0:09:c4:7b:d0
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 1500000
Changed.
Configuring flash size...
Auto-detected Flash size: 16MB
Compressed 3908 bytes to 1496...

Writing at 0x00001000... (100 %)

Wrote 3908 bytes (1496 compressed) at 0x00001000 in 0.0 seconds (effective 1803.3 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting via RTS pin...
=================
Burn Successfully
=================

Core 2 Freezes

COM Monitor Output:
=================
COM9
=================
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
ets Jul 29 2019 12:21:46

(The above loops infinitly until I re-burn the Core 2 using EasyLoader_M5Core2_FactoryTest)

I'm running into the same issue. Right after

"Hard resetting via RTS pin...

Burn Successfully"

The m5stack display freezes and in the console output is:

rst:0x10 (RTCWDT_RTC_RESET),boot:0x17 (SPI_FAST_FLASH_BOOT)
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
invalid header: 0x4f44213c
ets Jul 29 2019 12:21:46

on an infinite loop.

Even after re-burning it with the easy loader when I attempt to burn UIFlow_Core2 the same issue occurs. Any advice is greatly appreciated.