Create website internal server error

There is definitely something wrong you should probably check mariadb settings for cyberpanel are correct if there is no errors displayed for django side of cyberpanel. The easiest method would be MySQL optimization on CyberPanel - Docs - CyberPanel Community if you are not interested in their services you can do it manually by optimizing your mysql installation

OR (workaround)

Use the CLI to create your website

cyberpanel createWebsite --package Default --owner admin --domainName mytestdomain.org --email [email protected] --php 8.1