CM1000 - Strange speeds and behavior (Comcast)

[RM1030]

I'm curious if anyone has had a similar situation as I have with their NetGear CM1000. I've been waiting for a few days for a reply from support and figured I would post here in the meantime.

I had new gigabit fiber installed into my house. Upon installing the CM1000 it was only pulling around 1-4 mbps down and 40 mbps up. We tested a couple various Comcast modems the tech had with him and all were doing from 700-900 mbps down consistently. I told him I would figure it out and I ended up just turning everything off and power cycling the modem. After 5 minutes I plug it all back up and it worked fine and was pulling 968 mbps down. The next day I load up and I'm back to getting 1-4 mbps down. I repeat the power cycle and it works. Sometimes it holds for hours and sometimes for minutes. There are also times of constant time outs.

I've called Comcast and they state there is no line noise (I also see no line noise on Frontier speed test) and all signals look strong. I really don't want to keep power cycling my modem to get consistent speeds. The tech only guessed that the receiver on the back of the modem is defective and to reach out to Netgear since their modems they tested worked fine for prolonged use. I REALLY don't want to use one of their meager gateways...

Signal pictures below.

Firmware Version 

V3.01.04

[vkdelta]

signal levels look ok (except the fact that DS signal is bit high). Comcast recommends it below 7dB.

have you checked the comcast modems for prolonged use as well?

Please pull this power table and also most importantly even logs when you see low throughput and  post them here. do you see uncorrectables when the issue happens? 

[RM1030]

The tech had his plugged in and running for about an hour with no issues. He said I could go rent one to use for testing and return it within 30 days and not be charged. Not sure I trust Comcast enough to try that.