This could depend on how Firefox is set:

• Start up with Custom home pages
• Restore previous session

With custom home pages, Firefox should do a fresh request, but might used cached pages. With restore previous session, Firefox usually displays whatever is left in the browser cache from the last time. Since mailboxes are built dynamically by retrieving the latest content, the cached pages probably aren't useful.

I don't know if that's relevant to your setup; it's the first thing that came to mind.

I previously had it set up under "Home" then "Home Page and Windows" set to "use current pages" which included the 2 Gmail accounts. Since the update, these pages need to be "refreshed" every time I open Firefox but only Gmail...Yahoo mail works fine.

It works somewhat better the way you explained. Gmail page is still blank when I click on the tab but refreshes without me having to hit the "refresh" button.

I also find with Firefox that I have to re-set my options whenever they do an update...somewhat irritating and I tend to no update because of this.

It still doesn't work well but thanks for the suggestion:)

It's not worth the effort...changing to Edge. Seems to be no way to get Gmail to open automatically in Firefox.