c7000v2 Internet cuts out

Hello, i have purchased a Nighthawk C7000v2 AC1900 Cable modem/Router. I set it up with Xfinity and it worked great for about two and a half months. then the internet began to cut out every fifteen minutes or so. the only lights that would cut out are downstream and upstream. I called netgear and was informed that my power levels were not within the correct range.

I need to have -7 to +7 Downstream and 38 to 48 upstream. comcast came out and put a splitter to even out my power levels. it worked for about a week. my power levels are perfectly within range now and my internet continues to cut out once power levels begin to rise slightly even though it is still in the range provided by Netgear. Ive moved the box all over the house and to where the comcast line comes in directly. Please help this has persisted for over a month and nobody can seem to find a solution to this issue.

if you need any more information im happy to provide it.

For netgear employees that need more info. I still have the case number from my call to Netgear

Case# 428-79013