I asked this issue before. https://discourse.mozilla.org/t/cant-login-whatsapp-web-after-early-april-2022-update/97589 It's still continuing. Expansion: 新同文堂 facebook container ublock origin I tested a fresh install of firefox. Still can’t get login with the privacy mode. But the normal mode works. When I adjust the settings checking “Do not keep history” and “Clear cookies and website data when closing firefox”. It returned. After a new installation process, I stoped when I checked “Do not keep history” I speculated that this the effect. But no matter which browser I used, I save no browsing history records. Why only firefox got compatibility problem? Or did whatsapp work anything behind?