Problem with not being able to delete language settings

Hello,

I am having problems with my Windows 10 language settings and even though I tried a lot of solutions offered in other forums and by searching on the internet, I've yet failed to completely remove the issue, so as a last resort I'm writing here.

The issue is: I've recently bought a new laptop and I need 3 different languages for my daily work at university.
However for whatever reason, Windows 10 automatically added a fourth language (ISL). This fourth language is not visible in the language settings of Windows 10.
I can install the language package for ISL and uninstall it, which solves the problem temporarily, but after a couple of days (seemingly randomly) it reappears. That's really annoying as I have to often switch between languages when writing and the fourth language just gets in the way.
Is there any solution to this problem? I would be really glad if you could help me.