Possibly your work laptop has settings which clear out data such as history, cookies, and site permissions between startups? This could be a feature important to (enforced by) your IT department, or an unintended side effect.

Could you check your setting here:

• Windows: "3-bar" menu button (or Tools menu) > Options
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

In the left column, click Privacy & Security. Then on the right side:

In the History section, either:

• Firefox will: Remember history -- no problem

• Firefox will: Never remember history -- problem!!

• Firefox will: Use custom settings for history -- in the detailed settings this displays, check this:
  • "Clear history when Firefox closes" -- not checked, ok
  • "Clear history when Firefox closes" -- checked => click the Settings button and make sure Site Preferences are NOT set to be cleared

Hi, thanks for that, I have just checked & it is set to firefox will remember history

So is all other history, cookies, zoom levels, popup permissions, etc., retained between sessions and system restarts, the only thing that gets lost is Twitter's permission to send notifications?? Strange.

Yes, just the twitter notifications?

I don't know what else to check, that data should survive.

Sadly not, but thanks very much for your help & time.