Tabs lost when attempting to move tab group to new window.

[GWHAYWOOD]

When attempting to move a tab group to another window, only the first tab of the group is moved.

Sometimes, all or at least several other tabs in the group are closed.

They can be recovered from the list of closed tabs (if such a list is availble) but the process is extremely tedious.

[PikachuEXE]

To be investigated on... next week?
Would a larger number of tabs in a group make it easier to reproduce? Or do you have any extra info?

[GWHAYWOOD]

At the moment I am investigating whether or not the numbers of tabs in the groups makes a difference.

My feeling is that it does not, and that it is something about the actual page in the tab or the way in which the tab was created which matters.

Each night I shut down the browser. Before I do that I collapse all the tab groups and take screenshots of all the windows (at the moment I am running five windows, having moved some tab groups from other windows to experiment). In the morning I restart the browser and take another five screenshots for comparison. I have moved some tabs into new groups, to make some of the troublesome groups smaller, to see if the loss of grouping might be affected. AFAICT it does not appear to depend on the numbers of tabs in the groups. I have one group with 66 tabs which does not get ungrouped and in another window another group with only 15 tabs which does. Both groups have all tabs protected before closing and in both groups some of the tabs are no longer protected after the restart. In one window this morning, which contains only one empty tab and three groups (which contain 19, 13 and 4 tabs) in the grouped tabs every tab except the first tab in the group became unprotected.

[PikachuEXE]

I feel like this is a limitation of session store for unloaded tabs

Whenever a tab is updated (marked as protected, moved to new group etc.) an attribute is set on the tab elements
The extension would ask browser's session store to save these attributes

However I forgot when/where I saw this: changes to unloaded tabs sometime not persisted across browser restart

I will first need to reproduce it, then try it with all tabs loaded / most tabs unloaded

[GWHAYWOOD]

If that is the explanation then the symptoms puzzle me.

For example in my "RFCs" tab group, the one I mentioned which contains 66 tabs, I protected all the tabs.
I believe that I have loaded fewer than three of them since restarting the browser yesterday morning.

This morning when I restarted the browser, all except five of them were still protected.