To resolve the issue, we had to delete the "C:\Windows\Software Distribution" folder on each workstation.
I do not think this applies in my case becasue my log files are showing different errors, and the test computer I am using to try to resolve the problem does not have MS Office on it.
Still searching for answers if anybody has suggesstions.
Every other OS works fine, it is only the 2016 servers that have this problem.
It is definitely a WSUS server problem; if I go into the registry and change it back to Microsofts server it finds updates.
When adding new computers to the our Domain, I sometimes won't get anything.