Possibly related to Fonts Substituted And Missing In 25.04, and maybe even Kdenlive 24.04.0 NOTEXT appears in the menus
The open squares are the usual/common placeholder for missing glyphs in a font set.
I believe the fonts issue is known (and maybe already fixed in git?), the source of “NO TEXT” is a bit more mysterious, but seems like a locale file problem to me …