SMCD3GNV modem/router Intermittent Dropped Connections

[dandlion]

SMCD3GNV modem/router Intermittent Dropped Connections
ISP - Comcast Cable Internet
Modem model SMCD3GNV wired/wireless combo (2 pcs connected 1 wired 1 wireless)
Down Freq 584.999
Down SNR 36.8
Power 4.8
Modulation 256 QAM

Up Freq 35999435 Hz
Up Symbol Rate 5120 KSym/sec
Power 38.75 dBmV
Modulation 64QAM
speedtest is fine (when connection is online) 30 up 10 down
Location: Colorado Springs, CO

When the connection is online, the speeds are fine- the issue is the 2-3 times a day when the connection drops off. The error that we are getting is "cannot connect with primary dns server" however in our attempts to restore the connection we have:
Proper power cycling equipment
ipconfig /flushdns /registerdns /release /renew
reset TCP/IP
change DNS servers to OpenDNS or Google's DNS
Repair connection through Windows
Disable/Re-enable adapter

is there some issues in the area that we are not aware of? being that the signal levels are within range what do you think the problem resides in? FYI, both connections, the wired and wireless connections both have connectivity issues equally.