I am not sure if this because a newer version is installed.
Apple Mac M1 Firefox 142.01

It gets then worse from there. If it even manages to load a page switching between fields takes forever
Complex page, for get it it just hangs. Even on PC Windows 11, I have to kill the process with Task Manager

Then launched Parallels with Windows 11 on my Mac

It just gets from bad to worse.
Yesterday it was still working fine. I did upgrade my mac this morning to sequoia 15.6.1
I have no access to a pure windows laptop/pc, so not sure if it all caused by the mac.