Hi!
Check in Maya Preferences -> Interface -> Interface Scaling
and the DPI scale settings for the OS.
You can also try a reset of your preferences.
Rename the folder prefs in folder 2020 to something like prefs_backup, or to reset everything, the folder 2020 to 2020_backup (or even the maya folder to maya_backup). Maya creates new folders (don't copy preferences from previous Maya versions). Detailed at:
https://knowledge.autodesk.com/support/maya/troubleshooting/caas/sfdcarticles/sfdcarticles/Reset-May...