Banking partners residency screen gives me an ‘undefined’ error when trying to submit. This loops back to the same page. This happens whether I use the iPhone app or web.

If you are having problems with the program or glitches, please try clearing your cookies and cache. 

How to clear your cache. 
How to delete cookies. 

If this does not work, I recommend trying another browser and checking your internet connection, ensure you are hardwired.

Try uninstalling and reinstalling the app. This may help.
It is possible that the site is getting more requests than what it is designed to handle due to the extraordinary circumstances.

If you need additional assistance you can contact an agent.