Maybe a bit tangential, but I have been having a difficult time using Google Sheets lately in Firefox (like starting about 2-3 months ago). I keep track of my expenses (like groceries) in Google Sheets and always use Firefox to do data entry. Nowadays, Firefox browser freezes for a minute or two when I load/modify cells in Google Sheets.

I only have one extension, 'muBlockOrigin', installed in Firefox and have been using that for many years, so I'm sure the extension is not getting in the way of loading Google Sheets. So that leads me to believe that Google is probably supporting less and less of Firefox.