iOS 2.0 2FA error

I’ve set up my HA with Nabu Casa and 2FA. I was able to login with the old companion app, but when I enter the 2FA code (after entering username/pass) the app (v2019.1) responds with a 404 error.

Is this a known app error? Do I need to update HA or config?

Connect manually and omit the trailing / in the address…