Since my post I found some more clues, from another thread and from 45 minutes on the phone with a very friendly but not sufficiently knowledgeable TT rep.
It has been suggested that the TT business desktop state fiduciary download will misbehave until the state forms are actually ready. The TT business desktop app itself doesn't know this, so it provides no information.
There is a table here that shows 'forms ready' dates:
https://care-cdn.prodsupportsite.a.intuit.com/forms-availability/turbotaxbusiness_states_windows_sel...
It is shockingly hard to find this page on the intuit site, and the support rep did not appear to have this information. The state I care about showed a fiduciary forms ready date of March 1 when I checked a few days ago, and then today (Feb 29, 2024) the ready date now appears as March 8. Wonderful. Of course this is all theory, because the page talks about forms being ready, not my bought-and-paid-for software functioning.
General information about this appears here: https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-forms/s[product key removed]abi[prod...
So, for now, I am dead in the water.
