It seems that it was fixed upstream: https://bugzilla.mozilla.org/show_bug.cgi?id=1866409
- Bug#1056616: firefox: Firefox tab freeze when using ... Florence Birée
- Bug#1056616: firefox: Firefox tab freeze when u... Sebastian Reichel
- Bug#1056616: Firefox 120 tabs are freezing Nelson A. de Oliveira
- Bug#1056616: firefox: Firefox tab freeze when u... Vincent Blut
- Bug#1056616: firefox: Firefox tab freeze when u... Vincent Blut
- Bug#1056616: firefox: Firefox tab freeze wh... Nelson A. de Oliveira
- Bug#1056616: firefox: Firefox tab freez... Sylvestre Ledru
- Bug#1056616: firefox: Firefox tab f... Nelson A. de Oliveira
- Bug#1056616: firefox: Firefox ... Nelson A. de Oliveira
