Sometimes I noticed that my community site language has changed, even when I don't actually change it. This usually happens when I want to view my projects via navigation bar. I do not even hover the language thing (globe icon).
What's happening and how to fix?
I think it's time for you to get a new computer given all the strange things that happen to you 
get a new computer
this also happens on my mobile phone, so it's not a computer problem
This happened again...
I do not choose the "language" thingy
Random language? "Catala" is related to your phone/computer locale?
Maybe you are using a "private mode" or some form of privacy shield ("hardened" browser, antivirus, firewall) and your preferences are wiped out at some point.
maybe a vpn...
No, that's not my computer locale. I don't know what's exactly.
If you're using Tor, the website might be being retrieved from another country.
No, my laptop is a Windows 10/11 with Microsoft Edge 107.