Just checking, when you say you tried the highest PPQ, you changed from 120 to 960, yes? Actually, I think that would be counter productive here. It doesn't go lower that 120, the default, but does that help or hurt?

In newer versions of BIAB, look at Edit, Slide Tracks. In older versions, it was under the Play menu. Are the checkboxes checked for slides and humanize? Turn those off.

Audiotrack already mentioned, your BIAB tempo is limited to an integer. However, in porting BIAB files to a pro studio, I have found that precision isn't always there. In other words, a rendered file at the tempo of 120 might come into a pro studio at 119.87; something like that. I don't know a workaround for that unless the DAW software has a snap function.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.