Question about ISP service and Nano Prem. 2

My friends internet service provider recently had a large failure of service and thousands were off ... When they came back up, the prior great working Nano prem 2 now will not get a picture although it says connected ?? All computers and WIFI works well ... When the Nano Prem. is disconnected and reconnected on another ISP , it works great ?? Anyone have any advise or can share any type of test to see why ???? (She contacted the ISP and got another Modem and asked if any new filters had been installed and the answer was No)

I am surprised that with all the experts and experience here, others have not had a simular problem .... (but it's my first time also) Tks

does it work on free channels

She gets all fta and the free Ch's ...........

Couple of things to try would be reinstalling the p$ in another slot.
If there is a spot in server section where you can hit "connect" to server even though it says connected.
Leave it on a known working channel for a while.
And or also lastly try reinstalling factory file then the latest, scan and install the p$ again.
Good luck