Thanks for the reports. Alek is aware of the banking bugs and working to resolve them.
It was never possible to use proxies in mirror mode. The warning when you started mirror mode stated such. Think about it, mirror only runs after the game has connected to RS. So, by the time we can do anything, the game is already connected (without a proxy). If you want proxies, you're going to have to set it up prior to the game connecting. That's on you to handle since it's beyond the limits of mirror.