A subscription has been created wrongly after trying to import it from another system. The site works fine but the ownership is bugfix

saserv and when trying to change the ownership that is indicated on the subscription (and exists in /etc/passwd) it will not allow me.
I can change owner to root

saserv but not to any other user setup via Plesk on the interface for the subscription.
It looks to me is preventing also changing the SSL configuration, as I can override nginx.conf for others but not this one.
11.5.30 Update #51
CloudLinux Server 6.5
Any ideas ?