Talk to Aggressor Zo'dash in Oribos. Both the player's bank frame (empty, obviously) and bag frame are opened.

PLAYER_INTERACTION_MANAGER_FRAME_SHOW 53

Repro steps below : #19 (comment)

ooh, cool!

I've been trying to find an example of PLAYER_INTERACTION_MANAGER_FRAME_SHOW but didn't know how to trigger it!

Repro steps aren't as simple as just talking to the guy.

1- Talk to your banker.
2 - Walk away without closing any windows yourself.
3 - Talk to upgrade guy.
4 - Profit??? :(

There's an unhandled bank closed but still open thing going on I guess.

Incredibly, this seems to be a blizzard bug!

With no addons loaded following your repro steps the game fires BANKFRAME_OPENED when interacting with the Item Upgrades NPC. They have very obviously messed up the half-transition to PLAYER_INTERACTION_MANAGER_FRAME_SHOW (and HIDE) and are triggering BANKFRAME_OPENED for more than just the bank NPC.

I think it'll take me a little while to figure out exactly how I should handle it.