Playback Issues

First of all I wanna say how brilliant the playback in musescore 4 sounds! Especially the chambermusic sounds much better than noteperformer for example. But Im having some pretty weird issues. The dynamics often times dont fit to what I notated, and will even be different after changing something unrelated in the piece. Ive been having trouble with this for a while. Now today something even weirder happened. My whole piece has been transposed a half step down without me doing anything. The notes are still all the same, but they sound a half step down. I really want to use musescore because i really like how it sounds when it works, but unfortunately the more I use it the bigger the issues become. Is there anything I can do to fix this? Am I doing something wrong?

edit: Another problem now. If you check the mscz file i provided the cello part is rythmically ahead in some sections, most notably in measures 30 to 34.