edit: Oct 2 This didn't solve the problem. i.e., it randomly still reappears sometimes.
https://sh.itjust.works/post/3128264
edit: I refreshed firefox and except for one website, whatsapp and other websites seems to be working fine. Make sure you save the extensions and extension settings (and if you are not logged into your Mozilla account, everything else before you do it, even the themes, I lost a good theme because I didn't save it and even my mozilla account didn't sync it back)
I posted this a few days go and I am facing the same problem even now and I was wondering if someone knows how to make the clipboard paste thing work like Normal.
I am using Linux. I can't paste images in some websites and texts in some websites at random times. One time it might work and another time it might not work. It was supposed to be a bug which was fixed by Monday (this monday), but it isn't fixed and it persists no matter what the state of dom.event.clipboardevents.enabled