i am finding that firefox loses keyboard input after a while. the time period varies. i've seen it happen in as short a time as around 10 minutes. i've seen it work OK for many hours then lose it. and many times i don't see it happen at all (maybe it would have happen if i had continued, IdK). this has been going on for over a year. i don't recall the first version i saw it happen but i have Firefox 67, now, and it still happens. it seems to mostly happen on YouTube but it has happened on other sites. when it happens i can still type into other windows OK, and the mouse keeps working. it affects the whole browser, even if i visit other web sites, though i have click on links since i can't type in a URL. if i open a new browser window, that has no terminal input, either, making me think it is not an issue with X. if i quit firefox completely and start a new one, the terminal works, again.

has anyone else seen this?

i am running Ubuntu Xenial 16.04.6 with Xfce now, but i was using Unity when i first saw this happen. i last upgraded a couple days ago.