Check the first preference in Settings. It is at the top of the General page: "Open previous windows and tabs". You should NOT have that checked/ticked.

Thanks for the try but that was one of the first things I checked. I do believe it started with the last update. I am open for any suggestions.

Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox Title bar, especially if you have multiple windows open to prevent losing tabs in unnoticed windows.

• "3-bar" menu button -> Exit (Power button)
• Windows: File -> Exit
• Mac: Firefox -> Quit Firefox
• Linux: File -> Quit

In case you use "Clear history when Firefox closes", try to disable this feature

• Settings -> Privacy & Security
  Firefox will: "Use custom settings for history":
  [X] "Clear history when Firefox closes" -> Settings
• https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox

• clearing "Site Preferences" clears exceptions for cookies, images, pop-up windows, and software installation and exceptions for passwords and other website specific data
• clearing "Cookies" will remove all cookies including cookies with an allow exception you may want to keep

I have been using the Exit in the menu (3 bars) but find that FF still reloads sites that I was on. I had been on a Banking site closed it with exit then closed FF later when I opened FF it loaded up the Bank start page. It doesn't seem to mater how its closed sometimes it restarts the last site I was on.

  Also sometimes I get this warning when I go into FF as if it didn't fully close the last time it was open.

I just double checked my settings and found the; Settings -> Privacy & Security Firefox will: "Use custom settings for history": [X] "Clear history when Firefox closes" -> Settings

had gotten unchecked I'll need to try it for awhile again. Sorry to be a bother. Have a great day