I am using the 64-bit alternative of Firefox - Waterfox. I have been facing this issue even when I was using Firefox. What happens is after I have played at least one video or have kept it open for a long time, the browser and consequently all windows of applications start acting sluggish. By sluggish, I mean the following behavior:
- Laggy animations of tabs / progress bars etc.
- Delay while loading images
- Delay in text fields while moving around the cursor
The only way I am able to restore the smooth behavior is by a restart.
Any idea what's going on?