Update.
I just went through every step again, trying different bass parts - and it's working.
Go back to previous Bass parts that didn't work. Guess what? They're working.
So, my current status is that Sampletank is working for all instruments.
Did you try reassigning everything?
HTH
Trevor


BIAB & RB2026 Win.(Audiophile), Windows 10 Pro & Windows 11, Cakewalk Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Session Keys Grand S & Electric R, Kontakt, Focusrite 18i20, KetronSD2, NS40M, Pioneer Active Monitors.