Edits cause other elements to visually move in the score

Hey, I found out that in my score, for some reason, arpeggios keep disappearing. And I think I know how:

1. Open the attatched score: Awesome Anime Music.mscz
2. Check ŵhether all the Piano-arpeggios (the curvy lines) are present and complete (they should span the entire chord, just as they're supposed to do.)
3. Be especially aware of the arpeggio in measure 15. This is the one that I can dissolve consistently.
4. Go to to measure 13 and find the three triplets that are pointing downwards.
5. While holding down the Control-Key, select their bars.
6. Press (x) to flip the triplets up.
7. Check the arpeggios again. The one on measure 15 (and maybe other ones as well) should have partially disappeared.

Workaround: After they retract, stretch the arpeggios back to their full length and hope that there isn't another thing that makes them disappear again.

My PC: Linux Mint 20 Cinnamon
OS: KDE Flatpak runtime,
Arch.: x86_64,
MuseScore version (64-bit): 3.5.0,
revision: 43c5553

It's REALLY annoying for the score to keep changing behind your back, especially if, for a few hours, you have no idea why this is happening.
(I also have a strong feeling this might also happen with Crescendo-lines but I haven't found a way to replicate this particular disappearance. They used to be at measure 19-21 and all at once they were gone.)