Possibly a duplicate of another documented bug, but includes a solution to anyone experiencing the same.
Went to delete my “Keys” stash Category after moving its associated child Tab to another existing category.
Deletion removed my Sentinel category instead, and its contents (1 tab, yellows and idols) were hidden from view.
Repeated deleting Keys again to confirm bug, removed Mage category and hid contents.
Re-created (new) Category, Sentinels tab contents showed up under it. Did the same with Mage to restore that tab as well.
Peculiar, but thankfully no data loss. I’m staying away from deleting any tabs in the near future, just in case.
