Well, seems we figured out one thing... starting a game up from scratch, Trust mode works just fine the first chance you have to switch to it. Seems our 2nd battle in an operation, 70-turns in is a condition of the problem. No idea why, but there it is. Going to revert back to regular mode.
If anybody has any ideas, though, they'd still be welcome. Would like to know what's what and even work around it if possible.