Delver's Bounty Hidden Trove locked, un-openable after multiple T11 delves

Used a Delver’s Bounty Map. Completed a T11 delve, at the end the Hidden Trove is there, but says “locked” in red letters and unopenable. Multiple forums posts about this over the weekend. People say logging in and out, logging on another chr first, completely exiting the game, deleting WTF and Cache folders can fix, but NONE of that has worked for me.

The “Delver’s Bounty” buff is still on multiple characters that used the map, but encountered this bug, after doing TWO extra T11 delves to see if I just needed to do another one.

Hidden Trove is STILL there, STILL locked, and and STILL have the “Delver’s Bounty” buff.

In addition, after yesterday, logging off a character in the Delve treasure room now boots me out of the delve upon login, rendering the Delve dead - so now relogging isn’t even tryable (it didn’t work for me anyway)

I tried logging on non 80s, characters on different realms, opposite faction. Nothing worked.

EDIT: posted here on the suggestion from GMs in game, as they replied twice saying its a bug and there’s nothing they can do.