Issue Clean install via Plesk results in login loop

[kongo09]

On a rather fresh virtual Ubuntu server, I installed NextCloud using Plesk Obsidian. The install goes through without any complaints or errors. However, when I try to login for the first time, I end in a loop, always coming back to the login page. There are no errors.

System:

• Ubuntu 20.04.3 LTS
• Plesk 18.0.40
• Apache 2.4.41
• php 8.0.13
• MariaDB 10.3.32
• Plesk NextCloud package 1.6.1-109
• NextCloud 23.0.0.10

I read many posts about similar problems. Some people in similar situations report that a mobile app login works. Not in my case. The `nextcloud.log` file remains empty.