Hi @tacmonkey - I had a similar issue trying to capture audio with my m5stick. I had success using:
SD = 34
WS = 0
SCKJ = -1
The clock listed as pin 0 on the sticker on the back of the M5 Stick seems to actually relate to the word select clock. The code I was using required a value to be assigned for the SCKJ so I just set it to -1 to pass through an undefined pin value and this worked. I don't know if this would work in your particular situation but thought it worth passing on because it worked for me.