Graphical and playback issues with the new update

I'm having issues regarding the playback of scores. First of all, the loading of samples when opening a score has become noticeably slower, and the playback itself only visibly lags on smaller scores but also stutters audibly in bigger scores. I've already increased the buffer size. Also, with the new update some text seems to surrounded by additional outlines that make it look blurry, see screenshot. I've never had issues this severe since the very first version of musescore 4 and my system should have the capacity to run it. What can i do?