Javier,

This is tricky, as neither Taylor (macOS 12.0, M1 Pro) nor I (macOS11.5, M1) can replicate this. If you are having this problem, it is likely others will. I develop MRIcroGL on an Apple M1, and the dmg file is notarized by Apple.

1. What do you see if you run this from the terminal:
 sw_vers

2. What do you see if you run this from the terminal:
 locale

3. What do you see when you launch MRIcroGL from the command line, e.g.
 /Applications/MRIcroGL.app/Contents/MacOS/MRIcroGL

4. What do you see when you reset MRIcroGL from the command line, e.g.
 /Applications/MRIcroGL.app/Contents/MacOS/MRIcroGL -R