Site language changed from English to Russian

Hello. Somehow my site language changed from English to Russian without me making a change. I submitted a request with my host to restore to a version prior the time I saw the change.  I went to settings and verified that English is still set as the default language.  Any thoughts on what is going on?

Hello whoami18!

If you have the installed 2 or more languages then Dolphin tries to grab the info about your preferred language from:

1) GET argument;

2) POST argument;

3) COOKIE info;

4) from profile settings (for logged user);

5) from browser setting;

6) form the default on the server;

So maybe from your side now smth has been chosen from the 1-5 variants?