Progressive Industries EMS and Powerline frequency error

I had the same issue with my progressive in one campground. I was getting the frequency error and one side was reading 89. I had no clue and the book said to call customer support. I tried but no one answered the phone.

The EMS has worked perfectly in the month and a half since in different camp grounds.

No idea what high frequency will do so I did just as the OP did and unplugged it for the night.