I have tried to add Languages Again .Used 2 different English Languages to check as well but in the end it never changed or show any difference.
I have tried to run it on safe mode.
I have checked on the Computer Language.
At the moment it has the language pack English and for date-time format in German.
I have restarted obsidian just to be sure.
all resulted in nothing.
The suggestion seems to be not in anything ?
first I thought it is suggesting only Turkish but they seem to be not Turkish as well. or not well known Turkish words.
I believe from a quick read these may support your use case of multiple languages. In the screenshots it appears that Turkish was the active language, since you had it selected and then it swapped to English when you removed the others. I believe the implementation capability of obsidian core is one supported language can be active at a time for spellcheck.