Hello. I've had this problem for over a month now ever since I switched to Firefox from Chrome. '''Problem:''' Every once in a while, Firefox will suddenly be really slow and not load a page. When it finally does load, all text on the website is in the first font alphabetically on my computer. (I tested this by adding/removing fonts on my computer to confirm it was doing this and not just loading a specific font. I have a lot of fonts because I'm a graphic designer, and it's always picking the first font I have when they are all listed in alphabetical order.) This problem can occur on any website. '''When the problem occurs:''' I thought it might be occurring when the computer or Firefox was low on memory, because the problem happens a lot more often when I am working (and thus have lots of programs and tabs open) than just browsing. I started working with both Windows's Task Manager and Firefox's Task Manager open so that when the problem occurs I can check to see what is happening. Memory usage when the problem happens is kind of high, usually around 50-70%, with Firefox being the most or second-most memory-intensive task in Windows Task Manager. But no other programs on my computer are slowing down when Firefox is, and Firefox's Task Manager is not showing any one tab/add-on using more than "Medium" usage. (Although notably, the tab that is having the problem is not showing up in Firefox's Task Manager at all.) '''What I have tried:''' * checking and unchecking "use hardware acceleration" settings in Firefox. (It doesn't seem to matter, the problem still happens) * changing the default font settings in Firefox * closing and reopening Firefox. (This does fix the problem temporarily. After reopening Firefox and restoring the session, all pages load normally. But the problem will happen again later on a different site.) * restarting the computer (I shut down every night and turn the computer back on the morning. This problem still happens almost every day and often multiple times a day.) * Having fewer tabs open. (That does seem to decrease the chances of the problem happening, but it does not decrease those chances to zero. The problem has occurred with as few as five total tabs open.) * Checking add-ons (I'm not using very many add-ons in the first place—uBlockOrigin, Don't Accept webP, I don't care about cookies, and AutoDelete Cookies.) All of them are showing no or low usage in Firefox's Task Manager. I am running Windows 10, Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz, with 16GB of RAM. Has anyone else ever experienced this issue? Does anyone know how to fix this? I'm really sick of having to close and reopen Firefox in the middle of work.