If this is not the right StackExchange group, please advice.
I seem to have the same problem as 1 (2019, on the miniDSP forum, unanswered) with the NotWired NW-AUD-ICS52000 boards. I have had no other boards with which to test the TDK InvenSense ICS-52000 mics.
I do hear noise, that's all, all the time. But it differs somewhat in quality. But it's kind of whiteish noise I'd guess.
For me it's a long story, I have fiddled with my own driver in xC, running on XMOS boards, and scoped everything during the development, and found out that it must be the board (99% confident). Using the same SW driver for the PCM5100A on 3, the headset mics do work. I have also tested the headset driver with a sine of 640 Hz and it sure beeps.
I have scope pictures that I can publish. Since I discovered someone else with the same problem my confidence that it's the board rose from 50% to 99%! This is a hobby project so there is nothing I can't disclose.
Even for the 99% I do have some questions that I might make another thread for. Like, is the InvenSense ICS-52000 data sheet 100% correct? Or, is there no contradictions in it?