Hi Glenn, this is a puzzling problem. Do have a separate extension named Multi-Account Containers installed? Usually if you started a new profile from scratch you wouldn't have any extensions, but if you signed in to your Firefox Account, then Sync might have brought some things in.

As you probably know, you can view, disable, and often remove unwanted or unknown extensions on the Add-ons page. Either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• type or paste about:addons in the address bar and press Enter/Return

In the left column of the Add-ons page, click Extensions. On the right side, find the "Manage Your Extensions" heading.

If there is at least one extension before the next heading -- "Recommended Extensions" -- please continue:

Anything here that sounds container or tab related?

I have added and then disabled the multi account containers trying to reset the containers to off. No joy.

Can you describe how you know that different tabs are opening in different containers?

I'm assuming thy are opening in containers because the tab has a blue stripe at the top of it. They ay be al opening in the same container

The active tab always has a blue stripe at the very top. If you multi-select tabs by using Ctrl+click, they also will get the blue stripe so you can see which tabs are in the selection. So that is all normal.

Doh, my bad. Thanks for your time.