According to this page https://kb.netgear.com/000036375/What-s-the-latest-firmware-version-of-my-NETGEAR-cable-modem-or-mod... the latest version of the firmware should be V3.01.12. My modem is currently running version V2.05.18.
Netgear does not allow the modem owner to directly update their firmware and instead says that it will be automatically pushed from the ISP side. However I have not received that automatic update.
Is there a way to trigger a modem update?
Have you first tried power-cycling / re-starting it ?
You could try hard resetting it to factory defaults by pressing and holding in the recessed reset button on the rear for 30 seconds. This can sometimes help pull a firmware load if it is actually queued / present on the system. You will lose any customized settings, and they will need to be re-configured from scratch if you do so.
Perhaps the Comcast engineers are still testing it ? There is a time period involved from when the manufacturer releases it to Comcast and when Comcast actually pushes it out (if ever).
OP has not returned. Dead thread from last year now being closed.