PowerBI Data Refresh will only work on one server at a time

We are running PowerBI on premise server and are trying to make use of the scheduled data refresh.  Our environment is divided into a Test and Production system, each of which uses its own Windows domain accounts and SQL Database server.  When we installed PowerBI server on our Test environment, everything worked perfectly until we installed our production environment at which time the scheduled data refresh on the Test environment ceased to function.

Thinking that this must be due to something on our Test system we attempted to troubleshoot but eventually rebuilt our Test system.  The moment we successfully executed a scheduled data refresh in our Test environment, our production environment ceased to function.  We rebuilt this server and sure enough our new Test environment ceased to function.

These environments share no resources or Windows domain accounts, but it is too much of a coincidence that we cannot get two of these to function at the same time.

Any thoughts?