CBR 40 not compatible with internet speed per xfinity

[Keela21]

For the past three months I have been contacting Xfinity thinking that my Internet connection was faulty. They came out and ran diagnostics on my Internet and said it was running perfectly fine. They did state "the CBR40 is having an issue handling the speed or maybe needs the firmware updated as it is showing incompatible."  Is there anybody else experienced this issue? What happens is every 45 minutes my Internet will go down could be for three minutes but has been up to 4.5 hours!  It has been very difficult to work from home when my Internet does not work. Should I just buy a new modem and router? I thought this was supposed to be the solution as it is a mesh system. Any help would be appreciated!

[FURRYe38]

What Firmware version is currently loaded?

Has a factory reset and setup from scratch been performed since last FW update? Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 

Might have the ISP re-prevision the CBR40...

Be sure to power OFF the modem for 1 minute them back ON.

Depending upon what the ISP requires, some ISPs require a Docsis 3.1 for 1.Gb speeds. the CBR is D3.0. Though it is capable of near 900Mpbs, it's not really meant for 1Gb speeds. I Think best max speed is 600Mpbs. 

Please post about this over in the Orbi with cable modem forum:

https://community.netgear.com/t5/Orbi-with-Built-in-Cable-Modem/bd-p/en-home-orbi-cable