I'm using a TM-7755 2VA 2CI Receiver

I have been having problems watching the scrambled channels on various satellites.

I have both T-rex and Diablo cams with the lates firmware and codes (both units are not in at the same time) and both have the same problem.

I have to constantly turn off my receiver before the channels will open. Usually the only way I can view them is accessing one of the channels that works from the viewing card first and then trying.

Are all receivers this problematic or is there a fault on the receiver?
Both cards are seen by the receiver and channels accessed via smart

Help please