Problem with writing Cyrillic in Bulgaria under forum

I tried to contact the administrators through the forum, but they have stopped this function. Can someone experienced or at least pay attention to the fact that under the forum for "BULGARIA" Cyrillic does not work. Before, when writing in Cyrillic, everything came out, while now when writing a post, comment, etc. the words/letters with the following symbol "?" appear in Cyrillic. This problem has been observed for quite some time, isn't it a week or two?

https://forum.warmane.com/showthread...20936&page=133