The Tabs from my previous session to not open when Firefox opens.

There are a few such instances

Check https://support.mozilla.org/en-US/questions/1588837

Hi,

Please check out https://support.mozilla.org/en-US/kb/restore-previous-session#w_check-history-settings (the "Check history options" section).

Thank you for the suggestions. All the setting recommended were/are properly selected. STILL no tabs are restored. If I use Task Manager and End Task, the tabs will reopen when Firefox ia opened again. This is a clumsy way to do it. It works fine on my other Dell laptop.

That's weird... Could you please try creating a new Firefox profile and see if the issue reproduces there?