If you have looped audio but the bar length is an odd amount, or very long, the sync doesn’t seem to like this and sees it as a different tempo than what it is. I have created some loops out of drum improv, and the loops vary from 2 bars of 4/4, 3 bars of 4/4, 3 bars of 5/4 + 1x 3/4 + 3 x 4/4. All the exact same tempo (as I edited to grid first) but half this library does not playback correctly and it’s all the stuff that is odd.
But time signature/audio length shouldn’t matter should it? the BPM is the same regardless with the length. Manually entering the BPMs doesn’t change anything either.