When trying to open a joint account I go through the steps of selecting who I want to create the account with and then I’m prompted to authenticate.
I have fingerprint authentication enabled so I get a popup for it but after a second the message is replaced with red text indicating I need an RSA key (sorry I should have taken a screenshot) and I can go no further.
Disabling fingerprint authentication meant I was prompted for my pin instead and I was able to complete the process, I’m just raising this in case it helps someone else
OS: Android 8.0.0
Device: Sony Xperia XZ1 Compact (G8441)
App Version: 2.27.0