Unable to configure the Proxy on one of Primary Sites using all of the same accounts in AD because of the error:
However, on other Primary and Secondary Sites everything works fine.
The following error persists in
D /pma_isv_proxy_config:424:130c/ A certificate for '' and SCCM site '005' is registered with SMS provider but corresponding certificate in local certificate store is not valid or does not exist
Parallels Management for Mac Proxy server installed on the machine with IP that is not included in the subnet of site's AD.
Add your the machine's IP in the subnet of site's AD.
You can check this in the Active Directory Sites and Services: