Region playlists only working for some tempos Working for 120 125 and 126bpm but NOT working for 119 121 or 127 bpm!!!!

[JasonTurkMusic]

I'm getting very strange behaviour when trying to use region playlists.
My time area lights up red to show me I'm getting audio dropouts at the beginning of each region when repeating.

This doesn't happen for all tempos though.
It works perfectly at 120 bmp but if I adjust it to 121 or 119 bpm I get audio dropouts at the beginning of most of the regions.
See Video: (sorry OBS didn't capture the dialog box where I typed in the bpm but you can see it change after I confirm)
https://github.com/reaper-oss/sws/assets/157719230/c5073215-0190-42b3-9fe1-290dc2024578
There's no sound on the video above but the audio dropouts are bad enough that the first beat usually starts with a pop or is left out altogether
Even more bizarrely it works perfectly at 125 and 126 bpm!...but not 127 bpm!

There's definitely a limited number of tempos that work
WORKING
60
70
120
125
126
NOT WORKING
60.2
61
71
119
121
122
123
124
120.01
120.02
120.03
120.04
120.05
120.5
120.001
interestingly 126 works..but NOT 126.0001 (A separate reaper issue here unfortunately: Reaper "thinks" it rounds 126.0001 to 126 as it displays 126 instead of 126.001 in the timeline and in the panel at the bottom. But the audio dropouts still continue until I type 126 into the dialog that says 126 in it, there's obviously some discrepancy where reaper is rounding the displayed number but not the project itself)

This is a real pain for me as I'm hoping to use region playlists as a drum machine for Céilí dances but I need fairly specific tempos and unfortunately 119 and 121 are needed!

Any thoughts on what's causing this?
It makes region playlists unusable for me unfortunately which is annoying as I've already spent a lot of time working on them for this purpouse.

Any help would be much appreciated.
Things I've tried
I've restarted reaper,
restarted my computer,
tried ASIO drivers,
Tried direct sound on windows,
increased the audio buffer size (was 512, tried 1024, any numbers bigger than that require the region to be longer or the region playlist won't work, I tried it anyway with 3k buffer and 10 second long region but there was still the same dropout)
Glued the drum sound so it's not stretched
I tried a new project, strangely in that project 120bpm didn't work! I gave up then in disappointment!

[cfillion]

Does it still happen with this build? #1802 (comment) EDIT: with v2.14?