This question has to do with repeats, tempo changes and playing techniques that are triggered by note length. I’ve found that when repeats are not involved, tempo changes will trigger note-length-based playing techniques correctly. But if repeats are played, tempo changes after the repeats will either trigger note length PTs incorrectly or not at all (whether any changes get triggered seems to depend on how much music happens before and after the repeats.)
I made a really simple project using the default HSSE+HSO+GASE (Pro) playback template to demonstrate.
Ex. 1 No repeats, quarter notes at q=20 play a longer PT, at q=400, they play a shorter PT.
Ex. 2 Add repeats and only the longer PT gets triggered.
Ex. 3 Keep the repeats, but turn off “Play Repeats” in playback options, and the shorter PTs once again get triggered correctly at the high tempo.
As always, my apologies if this has been covered before. I spent the better part of an hour searching the forum and didn’t find anything relevant. (Win 11, Dorico Pro 5.0.11, also happens in 4.3.)