Hello Everyone,
Please allow me to chime in for a moment. We are dealing with two accounts here:
1. The Primary Site Administrator Account (PSA)
2. The Windows Service Account (WSA)
PSA
The PSA is a Non Windows account. It is not local to the windows machine, nor the Domain. This account is local to the ArcGIS Server itself, and only exists in ArcGIS for Server.
WSA
This is an Account that runs the ArcGIS Server Service, and can be either a local or domain account.
What it sounds like you did was reset the PSA Account, then you rebooted the ArcGIS Server Service. Resetting the PSA Account should have no bearing on the WSA running the ArcGIS Server Service.
What happens when you reboot a service is the WSA running the account is 'relogged in' or at least the credentials are repassed. It is possible that the account had a password flag on it for resetting it, or the password was changed somewhere, and the credentials on the ArcGIS Server Service were never updated. Restarting the service could simply bring issues like this to the surface.
Were you able to correct your issue? Thank you very much-