I am using the latest version of Firefox on a brand new IMac running 10.15.7. Since I got this new computer Firefox has been incredibly slow when accessing eBay. It can take forever to scroll through my image file to find an image to load on an eBay listing. When I try to scroll through the image file most of the time Firefox will freeze every 40-60 images and will not respond to the cursor movement for anywhere from 30 seconds to several minutes at which point it comes to life for a few seconds and then freezes again. I can do most other things on eBay and other websites except loading images. There is a second problem with Firefox. I frequently get the following error from eBay "https://www.ebay.com/n/error?statuscode=500. The problem is that this appears to be a Firefox issue. eBay directs me to go to home page and when I then try to reload the offending page I get the same error message over and over again, however if I close Firefox and re-start Firefox I can get to the page that generated the error message. I get the same problem with CanadaPost. Firefox gives me an error message telling me that the page doesn't exist. I closed Firefox and reload CanadaPost website and then I can get to the page. This happens multiple times a day and only with Firefox. Other websites and other browsers don't have this problem.