Hello.
Recently I’ve started to notice that, brushes in Weight Group mode do not keep their value… instead all Weight Paint Brushes share’s their values (which is not a good thing).
Brushes SHOULD not share their values among other brushes.
(No, I did not modify those brushes values… Blender transfers brush values from one to another)
I don’t know what causes this.
The only fix I find Is to use Factory Reset… but adjusting everything will take time.