On certain websites, scrolling to the top and bottom with the scroll wheel and then clicking anywhere causes text and shapes to “shift” slightly. This happens every time on some webpages, like phpBB sites, while on others it happens only partially or not at all. This does not happen when using Brave.
I’ve just tested it, it also happens to me on the phpbb site and here in this forum on the main site.
i found this but not sure if it could be related
Tested on a different distro + DE and it still happens, it’s a problem with Firefox itself.