Russian language encode problem

Hi

I have problem with Russian Language in all 3 nrelate plugins: flyout, related, popular – the titles of blocks is “???????”. Data stored in Data Base is correct, but the result is not correct. Here is screenshots http://prntscr.com/5ays5o, http://prntscr.com/5ays8m, http://prntscr.com/5aysgy

How I can fix this issue?

Thanks.

https://ww.wp.xz.cn/plugins/nrelate-flyout/