Pimoroni Pico Plus 2 - 3x PIO with MicroPython - FAILs

I tried MicroPython for new RP2350 board (Pimoroni Pico Plus 2):
The chip has 3x PIO, but the third one does not work:
I configure SM number with 8… - no complains in MicroPython.
But no signals coming out.
It works fine with PIO 0… or 4…, but not with 8…

MicroPython FW image not configured to make use of 3x PIO?