Reporting same thing on my end as well. Did a bank clean out of unnecessaries yesterday so I knew exactly what was in here and my “treasure tab” for social event rewards only accessible by me has been wiped of about half its stuff. Plus some other random stuff in other tabs, this is wild!
Edit: I opened a ticket and I suggest all GMs with this issue do the same.
Edit2: Dark Descendant of Light - Durotan
^ Suggesting bug reports > tickets