This is basically a copy of what I put in the Ubuntu forum. The problem is the same, no matter where I post it. Originally I was using Ubuntu 18.04 LTS. I thought it would be good to update to GG (20.10) though I did briefly try FF (20.04). As the install was done on an existing 18.04 version things remained the same for programs, book marks, etc. Ok, now the crunch: I '''USE''' Firefox ""A LOT"". When it loads, there are...... 8 x 6 windows of FireFox and each of those have anywhere from one to ""THIRTY"" tabs loading. Believe me: ""It worked!!"" I could use it, also run other tasks as well - though a VM was pushing it with the RAM. But the entire machine worked. Now, I am lucky if FireFox loads at all. Let alone let me browse. When it loads some of the window's tops are flashing. A screen shot does not really show this. (I tried) All that has changed is the O/S from 18.04 and Firefox from (what ever it was) to 83.0 I don't want this to be a finger pointing exercise between Mozilla and Ubuntu. I would prefer it is helpful to all. What have I tried? I've tried starting FireFox with all addons disabled. Still happens. I am going to try to remember to (next time) launch FireFox from a Terminal and pipe the output to a file to look for things. The machine I am using has shown it is well up to being able to have this running. I have had it working for a few years like this. This post is (for now) to establish there is a problem. I will post more information when I get it, rather than waiting to get it then post, as I feel there are a lot of people who have very similar problems and I want it known: ""You are not alone!"" Now a bit of extra stuff. Other things which are weird: When I am watching stuff - youtube for example - the playback is/WAS jerky. I hadn't touched anything in the settings. After digging around, I discovered that I had to turn ""OFF"" the hardware acceleration for the graphics. Question: How did it get turned on? (Semi rhetorical) I have a lot of local pages I open with passwords. When I load them the CPU load goes through the roof and nearly invariably the program just exits. No crash report. Which is a good 50% of how it happens. The other 50% is the machine just locks up and I have to power it down.