Ok that is odd. I haven't seen that in my Win11 install and neither have play testers. I ask because we used to have a combined Linux/Windows package but there were some things that broke in Linux.
I did find this on Renpy
https://www.renpy.org/doc/html/display_problems.html
You can try holding Shift when loading the game or pressing Shift-G once loaded.
I hope that helps.