Nextcloud doesn't allow access, despite address being whitelisted in config.php

Question

I installed an UCS Univention App virtual machine with Collabora integrated with Nextcloud. After installation I accessed Nextcloud without any issue, but I did't set a static IP. Next day I came back and Nextcloud refused access, DHCP assigned something else. I ran through updates, set a static IP and added it to the trusted_domains array. I've rebooted several times during the process and the issue is still there.

Answer 1

I've reinstalled my virtual machine and it works. I've also kept to the old version. I think there might be a problem with certificates or config files, that I've either edited the wrong config.php file or those certs stuck to the old IP address.