I have had that problem before as well. I have had it come up short by 10 or 20 bars, only render 1, render a bunch but not all. I have even had it not want to render at all.

Very random indeed! One thing was i had to fiddle with the bar count somewhere in RB.

Some files will not render, and I assume that the file is bad somewhere, but i have so much else done i have not wanted to change it yet.

Recently the last three bars went bad on one song, and it glitches about the third from the end bar, and then straightens out. Very weird.

HP Win 11 12 gig ram, Mac mini Sonoma with 16 gig of ram, BiaB 2025, Realband, Reaper 7, Harrison Mixbus 9 32c , Melodyne 5 editor, Presonus Audiobox 1818VSL, Presonus control app.