I have previously successfully logged into HA from this iPhone when I gave it a try via systemd quadlets, but due to wanting addon access I reinstalled in a VM HAOS on Arch host via KVM - #2 by patrikg
The problem now is that the HA application on this iPhone refuses to let me specify where the server is and gets stuck on this screen:
disable location permissions on your device for the HA app. this should allow you to get to the HA companion app settings, once there delete your server and close the app. reenable location permissions and reopen the HA app. it should request you to login.
I have disabled Zerotier One to deny the iPhone access to the home network and it turns out that the device somehow persisted the old login details for application even with the multiple removals.
After denying access, the application finally got out of the softlock and gave me access to the servers list, where I could delete and readd HA on the home network.
Very bad UX from both HA for not giving me a chance to back out of the retry softlock and Apple for persisting application data despite deleting the application.