@FURRYe38 Thank you for the rapid response and the suggestions.
Please post a copy and paste of the modems connection status page. - Image attached
Have the ISP check the signal and line quality UP to the modem. Done by on-siite tech. - Line noise from street all the way to the modem was under 40 (something) not sure how it is measured but I observed the test meter.
Be sure the ISP provisions the modem correctly. - How can I tell if it is correctly provisioned? I do know the starting frequency was originally set to 507000000. I upgraded the service from 200Mbs to 600Mbps. When the speed was not observable even when directly connected to the modem a technician was dispatched. He checked everything and could not explain why the speed was limited to around 200Mbps. Solution as you may have already anticipated, was to install an Xfinity profided modem. Result was speeds between 500 and near 700 Mbps were observed. I performed a factory reset on my modem and observed the starting frequesncy was empty. I then contacted Xfinity once more to re-provision my Netgear CM1000. The down speed remains around 200Mbps BUT the starting frequency was automatically set to 651000000.
Be sure there are no coax cable line splitters in the between the modem and ISP service box. - There are no splitters and the direct line to the modem was installed less than 2 years ago.
Be sure your using good quality RG6 coax cable up to the modem. - Suspect all is good based on recent install and line test as described above.
Be sure to power OFF the modem for 1 minute them back ON. - There were multiple reboots performed. As a force of habit I power down, remove the power supply, press the power button to bleed off any stored energy, wait a minute, re-attach the power supply then boot up.
Be sure your testing with a wired PC connected directly to the modem. Dont connect a wireless router. - Done as described above.
