so i'd been dealing with an issue for a few years where trying to search "images" would lead to a blank page that had nothing on it but the word "healthy". something about squarespace would be added to its URL. i didn't know what squarespace was until it started doing that, so it wasn't doing that from constant use of their site. my only extention has been uBlock, which does not cause that. PC's antivirus ignored it the whole time. clearing cookies / cache didn't touch it.
it kind of did nothing besides that, until trying to sign in to Kaiser Permanente years later, at which point because some of their URLs do contain 'healthy' it would get confused and try to chaotically re-paste and make a mess of the sign in page's URL so i couldn't use it on PC.
i had contacted squarespace i think it was a year ago asking about this and they seemed to not know what it was about, so it's probably not actually theirs.
i'm not asking Firefox to do anything here, because an effective built-in solution that seems to work was already suggested when going over the weirdness with Google's AI. mainly i'm posting in case anyone else has this issue, to point out that you should actually be viewing it as a serious issue and not as just brushing it off as a quirk that only vaguely effects one feature, because it's likely a form of malicious browser hijacking and who knows what else it's doing that you don't see.
to get rid of the thing, atleast in my case it worked by typing "about:support" into the address bar. this leads to a specific page in Firefox's settings which has the option to the upper right of the page to "refresh" Firefox. this isn't a standard refresh like that little circular icon to the top left that just reloads the page, morelike it restores the browser itself to a healthier state. and yes this will close any webpages that are currently open, it does not seem to reset passwords or erase the bookmark bar however.
