Absence of ellipsization in filenames in the filechooser buttons in comparison view can prevent the window from fitting the screen
The new UI in 3.21.2 using buttons to show the two files being compared in the side-by-side view looks pretty neat visually, but it prevents the app from scaling its window width down to fit the screen when you are comparing files that have very long filenames, such as
résumé d'année 2021 yearly retrospective, part C - short fuses and abuse - v2 common final harmonization.markdown
résumé d'année 2021 yearly retrospective, part C - short fuses and abuse - v3 common final harmonization, with 2022 focus opening
This is what it looks like: