When i go to the bank and click the banker i get extremely low fps with the bank window open. I go from a steady 60 to 15.

This only happens with bagnon enabled, perfectly fine if i disable it.

I also had this issue, however i found out that it was from another addon called "Can I Mog It?"

The issue only appeared in banks that had a lot of transmoggable items. Issue disappeared after disabling said addon, so if you also use that addon, i would try to disable that first.

I just made a change that might help with this issue. I've never had it, so we'll have to wait and see.