One sprite atlas I'm using keeps getting reverted to a previous state when building

I use two different fonts with relative atlases in my project (one for Japanese, one for alphabet languages).

I recently added French localization to my project, and I noticed that the font I was using was missing all the accented characters.
So, I modified the font myself, put it in the project, then used the font asset creator using the modified source font file, and a character set text file containing all the characters in the project.
The atlas gets generated, and it works perfectly within Unity.

The issue is, when I build the project, the font atlas gets reverted to its original state (without the additional characters). This happens before building (if I try the build it doesn’t have the additional characters).

I use PlasticSCM but I doubt that’s the source of the issue (it happens even if PlasticSCM is not open).
I’m on Unity 2021.3.6f1

On a similar but unrelated note, whenever I have to add characters to the Japanese font atlas (which by the way, has no issues when built), some of the settings in the font asset always go back to their original value (specifically: scale, ascent line and baseline are the ones I need to change every time).
This is more of a nuisance compared to the other issue, but I feel that’s not how it’s supposed to work.