Admin password no longer accepted

I have Nexcloud installed in a local Ubuntu -puter. This is a testing setup. Today the admin password suddenly no longer works.
I tried:

sudo -u www-data php7.4 /var/www/nextcloud/occ user:resetpassword admin

But got “user does not exist”
How do I create admin password again?

I have otherwise root access to this computer. I can also access the config.php.
The Admin folder exits at /var/www/nextcloud/data/admin.
admin record also exists at oc_accounts but not in oc_users.

The user commands can be found in the documentation.