Okay, thanks to @bordache (see this post), I finally understand why my vault and folder doesn’t want to sync with Working Copy : Accented name.
So, if Working Copy doesn’t work with synced vault, and your language use accent, it’s probably that (fact : I literally don’t see accent because of habit).
If you have an accent, and doesn’t want to check all file, you can use (on windows) the cool app named PowerRename (from powertoys). Using Regex, you can manage with it ! For me, I replace all é, è, ë… with E, and the same for “à”. One day, I will find a regex with all accented characters.
But, I have the same view as @necopinus, I don’t think Git/Github is a good usage for note, mostly if you have like 1go of file (Hello <3, it’s my case). I can afford 10$/month to have Google Drive + Obsidian Sync so I will use this.
But, if you can’t, using shortcuts to pull / push each time you open and close Obsidian, it can be good!
Also, if you are a student, Working Copy is totally free and offer many cool things. I use Working Copy since months because I love programming, and It helps a lot to program on Ipad.