Player playing sounds from multiple places in the score at the same time. At later parts in the score, no sounds play from the piano instrument at all. Seemingly only affects the piano.
This is all on the latest version of Musescore 4 as of writing (28-12-2022).
Play from the beginning or at any point in the score and it will be obvious that the piano does not play what is written. Or, alternatively it does play what is written, but also plays elements from way further in the score. Sometimes no sound plays at all, seemingly beginning at some point further into the score.
At the beginning the piano playback starts with a loud bang of all the keys (or something akin to that).
Measure 1421 stops playing the piano all together. Somewhere on page 53 the players starts playing only from the position it should be at. The measure being played at the start of the score are somwhere before 2869, probably 2850-ish.
I understand creating a score as long and big as this one is probably a pretty stupid and foolish thing to do to begin with, but I thought I'd report the bug since this didn't happen on Musescore 3.5 (or whatever version I was on last, I forget). It was laggy and prone to crashing on that version of the programme, but this has made the score unusable.