Firefox performance problems

I have an issue that in Firefox creating a linq or marking word as known is significantly slower than in Chrome. In Chrome it is almost instantaneous and in Firefox up to whole second from the time I press a button to make work known until blue box disappears.
Does anybody have similar issues?

What version are you using? I’m using Firefox 60.5.0esr on Debian and not facing these issues.

65.0 (64bit)