Hi,
Like the title says it's not possible to connect from the Teamviewer IOS app to a computer that has that same IOS device set up to approve TFA for connections. It just tries to authenticate, but in the app it never gives the option to do so.
A fix for that would be nice, or just let any universal 2FA app be able to use your QR code.
I can't find where to post bugs/issues, so I'll just leave it here.