I'm not the parent poster, but this happens to me as well. It's new and didn't happen about a year ago or before that. To everyone saying this is Snap: I'm usi

I'm not the parent poster, but this happens to me as well. It's new and didn't happen about a year ago or before that. To everyone saying this is Snap: I'm using Debian. It does not have snap. To everyone saying this is apt: no, I also do not apt upgrade and then wonder why tab processes suddenly can't talk to the master process anymore. Unattended upgrades is not installed on this system (it's not a server and I do manual upgrades regularly, it's not as though that unexpectedly reports that there aren't any to be applied). It happens both on systems where firefox-esr is installed via apt and where Firefox is installed directly from Mozilla without going through apt (stability vs. timely features). I do remember that this indeed happens when I once did upgrade via apt and then continued using Firefox. Similar effect with e.g. Signal.