Gmail says browser is unsupported just now, Firefox help says version is up to date.
I get the message: Gmail may not work well with this browser version. Please upgrade to a supported browser. Just got it today. FireFox is version 125.0.3 for Windows 11. On gmail help, it said to disable extensions and add-ons. I did this, restarted Firefox and get the same message.
Opaite Mbohovái (1)
You can remove all data stored in Firefox for a specific domain via "Forget About This Site" in the right-click context menu of an history entry ("History -> Show All History" or "View -> Sidebar -> History").
Using "Forget About This Site" will remove all data stored in Firefox for this domain like history and cookies and passwords and exceptions and cache, so be careful. If you have a password or other data for that domain that you do not want to lose, make sure to backup this data or make a note.
You can't recover from this 'forget' unless you have a backup of involved files.
If you revisit a 'forgotten' website, data for that website will be saved once again.