Does anyone have this issue were firefox becomes slow if left open for a long time. In my case after a couple of weeks rendering becomes slow and when I use youtube for example if is laggy, just trying to change volume taka few second to show the volume bar. It also happens to my laptop at work. I have around 30 tabs open.
Only the part with youtube. Don't know if they are pulling some tricks on uBlock users, but about 10 tabs of youtube can get nasty, even with a somewhat recent workstation.