Rated 5 out of 5 stars
Yep, came here to say that there is an issue with Facebook when writing in Russian and only in comments. It adds Latin letters in reverse of typed word for transliteration and it happens when you hit backspace, Del, or use '. So please take a look. I'm sure Facebook added something to their writing comments component as in all other places it keeps working flawlessly.
I've been using this add-on for years and it's definitely 5 star add-on! Thank you!
As far as I can tell, new version of FB installs a faulty key listener that does fully process generated keypress events.
Please report to facebook that there is an issue with a new version. I will do my best to find a work-around but so far I have not found any.