Unasked lines' reset shapes and positions

[ Edit: I'm on --> OS: Ubuntu 20.04.2 LTS, Arch.: x86_64, MuseScore version (64-bit): 3.6.0.487916429, revision: 1977cb3 ]

Hi everyone

I've been using Musescore for a bunch of years now, but mostly for pedagogical purposes. Nevertheless, only a few weeks ago I've decided to do my first compoitional project in it. I was much glad while the work seemed to run beautifully and almost flawlessly.

Until last night, when after adding some symbols more extensively for the first time, I noticed that the previous pages - which notation was already done - got all my lines' and symbols' adjustments messed up at once. Curiously the first page seemed to keep all positions and shapes, while all other pages got what I later understood as a generalized 'ctrl + r'-like repositioning.

As I guess it's quite improbable that I've mistakenly selected all lines and symbols across 3 or 4 pages and asked for a 'reset shapes and positions', I confess that I am very unconfident now to keep working on this project in MuseScore, despite I'm enjoying it so far. I take much time adjusting diagonals, horizontal adjustments, etc. Getting unwanted resets on that would definitely ruin Musescore's useability for larger compositional projects like this.

I hereby attach the messed version (suffixed '3') and a previous version of that same file (less complete notation but with the manual adjustments kept before the resetting happened). I would appreciate it very much if someone could help me discover if it was a bug that messed all it up or if it is more likely that I have been somehow asking for a batch resetting of shapes and positions, unaware of it (perhaps, a shortcut to do all this was mistakenly triggered...).

Thank you very much,
Paulo