The issue with delete instance affects only 10.4.2.2 and its described in the release notes.

Updating a Runtime Defined Entity (RDE) that contains restricted fields might fail if you remove an item from an array in the entity contents ...

https://docs.vmware.com/en/VMware-Cloud-Director/10.4.2.2/rn/vmware-cloud-director-10422-release-not...