Hey @bitmatic welcome to the community 
can you double check that syntax? → for built-in CODE I’m quite sure you may define that URL in plain syntax https://cloud.yourdomain.tld
occ config:system:set overwrite.cli.url --value="https://cloud.my.domain.xyz"
do check out How to manage Hosts and FQDN for Nextcloud snap even though you’re not using the snap… but there are some useful hints if you have issues.