I've encountered this regularly and I'm not sure if its an actual bug or just a nitpick.
Most times when I bring a 4 bar loop into a new Reaper project and want to adjust the project tempo based on the loop, Reaper assumes the loop is 3 bars long.
While this may be optimal for jazz players, I think it would make sense if Reaper assumes the time selection is going to be an even number of bars (especially in 4/4).
Tempos based on 2, 4, and 8 bars are all going to work (a 1/4 note just becomes a 1/2 note or whatever), but the same can't really be said for odd bar loops.
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