-create a blank Reaper project
-set the BPM at 75 (or 150, 75, 25...it seems this bug is affecting all multiples of 25)
-load a Kontakt 7 instance with any "Play Series" library (Cloud Supply, Modular Icons, Melted Vibes etc... any of them is affected)
-choose a preset that use a sequencer
-hit Play and keep any note pressed: the Kontakt sequencer will play, but starting with bar 33 it will speed up, going totally out of time. If you jump the cursor before bar 33 the speed will be right, after bar 33 it's totally messed up. If you switch the Reaper metronome on you will hear it very clearly.
I'm using latest updates of everything.