Stop working with some Russian characters

Hi,

Any online test page please ?

ok. look there:

keyword without “Й”
https://image.prntscr.com/image/7d8b7285f4e7461494193c65299afc68.png
works fine
https://image.prntscr.com/image/793d4d11d2fa43a69738225da30fa8f2.png

then I added a synonym with the letter “Й”
https://image.prntscr.com/image/6b9022e738874d6092154a6933245d28.png
the keyword is not active.
https://image.prntscr.com/image/7fa0c35a6d1744128edc2501dc8d7b08.png

no errors in firebug console
https://image.prntscr.com/image/277e7fe488124e01ae50a53258031b27.png

I can give link to the page, but you will need to set a domain name in windows\system32\drivers\etc\hosts

the impression that the extension in general is very crooked working with Russian characters.

russian
https://image.prntscr.com/image/ce505300f50a482492685ea774bc4f5e.png
doesnt work
https://image.prntscr.com/image/f4e27bd621a44444a721f7aa30e55859.png

no russian
https://image.prntscr.com/image/8b55cb4f216147f59d168c282e9a3bc9.png
works fine
https://image.prntscr.com/image/dd751f005c4f4fc3a53d7456fa2fcab6.png

any help?