This has happened to me a few times in the past my Man ..I posted about this on someone elses thread about them having this issue as well ... I think sometimes the browser's updates screw things up ... I wonder if you and I both have any of the same mods that would be causing this ... of course it would have to be a mod that is active on that script ..know what i mean?
I think for me it's either the "Canned Replies" or "Similar Threads on Thread Creationg"
https://vborg.vbsupport.ru/showthread.php?t=241309
https://vborg.vbsupport.ru/showthread.php?t=281113
I know that with the Similar Threads mod sometimes it freezes the screen and the auto save triggers but there is nothing being saved ...it wont allow me or others to starting adding anything until it feels like it ...
The canned reply does the same thing ...