Now when you create a tab in a group (user-created group ), it is added to the group. However, when the window is closed, tab ends up in “recently closed”, and an incomplete, outdated version of the group remains in “saved”.
It is necessary or remove from the group only those tabs that the user closed himself, one by one.
Another option: for user-created groups, automatically save (asterisk) all tabs when you create them (and remove asterisk when user close them).
It is also worth considering any windows as groups (they already automatically receive a title with the number of tabs). This will add all closed windows to “recently closed”. (now it is possible to group closed tabs by site and by the name of the group created by the user.) With this improvement, any closed window can be restored in two clicks, even if it is not specially saved.