[Sephiroth]

I didn't say the amp characteristics were a cause of the OP's problem.

But looking at your stats, Eeeps, or rather your closing statement - the fifth channel MUST be on the same line card as the others. You are terminated on one line card, not on two. Generlly speaking (but not mandatory in DOCSIS 3), downstream channels 2 onwards are separated by 8 MHz bandwidth, which is your case. The fifth channel arises becasue VM are load balancing across as many downstream channels as are available to a network segment and which have high SNR.