Since the latest (5 May 2022) update to Firefox (to Firefox 100.0) my Gmail account does not work properly on my desktop running W11. Gmail frequently disconnects for varying periods, then reconnects, only to disconnect again almost immediately. Gmail will not let me open another account from within the current account. This does not happen on my Android phone where Gmail works properly. Neither does it happen when I run Gmail through Edge on my desktop. Hence I presume it results from an interaction between Firefox100.0 and Gmail. My wife has exactly the same problem using her Microsoft Surface Laptop under W10 since this latest update.