It works fine until it decides to delete all containers, closing all your open tabs.

I like the idea. It doesn't work for me because it only shows icons. I often have multiple tabs open from the same website. These have the same icons.

It helps that tooltips come up, providing the full name of each icon if you hover for a bit. But the hovering takes too long. There isn't an option to speed it up.

One fix would be to provide a toggle that would display tab names (ideally, user-editable names) along with icons. Another would be to display tab names automatically when there's more than one from the same website.

Still has the same problem it had when I used it ages ago, which is that if you right click on one or more tabs to move them to a new group, the tab you're currently on will not move, and after that it won't move even if you click away from that tab and try again.

The user interface is also a bit finicky.

This is exactly what I was looking for to manage and categorize large groups of tabs. Unfortunately it doesn't work a lot of the time, which is disconcerting because it leaves lots of tabs inaccessible. I have to quit and restart firefox sometimes multiple times for it to work again as expected. When it's working, it's great!

After browser restart all tabs are gone, including panorama sets. Recovering profiles doesn't help. Where are the settings being stored?

My Tab Groups Randomly Resets All The Time

Sorry, The application works slowly, especially when switching between tabs and Panorama Tab Groups. This poor performance is since the fresh installation of this extension. It should be definitely improved.
I use FF Quantum 65.0.1 (64-bit) Portable version.

Two stars for effort but it doesn't work for me. When I click on the icon it opens up the tab groups, but all my other tabs disappear. There are no menu items or anything to move tabs into a group. When I first installed it a couple months ago it worked. Not sure what happened.