RectTransform scale of my Canvas changed when I build on Android

Hi, maybe I’m missing some things with Canvas. Right now, I have a Canvas on “Screen Space - Overlay”, and a Canvas Scaler on mode “Scale with Screen Size”. I think I always did that for my mobile apps and it was ok.
Anyway, this makes the RectTransform component of the Canvas have a scale of 0.318… and I can’t change it (why is this value, I don’t know). But ! I realized that on my Android build, this scale changes to something close to 1.3. As you can imagine, this causes a lot of problems, for exemple a simple move of an image is 4 times slower on my phone.

I can’t figure out a solution…

Anyone ? I still don’t understand what’s happening…