New cax80 received wired ports drop internet

[Lnmayer]

I received a replacement cax80 from NG due to bricked unit. The new cax80 was configured.
The problem that I am experiencing is that the internet disconnects from the wired ports. The wireless works fine. I have a netgear unmanaged switch which connects, tv, DVD, ring, garage door opener etc. The will all lose connection.

Spectrum checked the configuration and indicated that the cax80 was activated.

After troubleshooting for several days, I reconfigured the c7000 that I have and that works without issue.

The CAX80 was an expensive modem/router combo which I would like to see work.

Anyone else seen this issue?

[FURRYe38]

What Firmware version is currently loaded?
Are you using the multi gig port or just the 1Gb LAN ports? 
Be sure your using a good quality LAN cable between the modem and wired devices. CAT6 is recommended. 

What is the brand and model# of the switch that is connected? 

[Lnmayer]

Switch is netgear gs316. The fw was the latest version. I will purchas cat 6 cables. I was connecting the switch to the gigbyte port and my qnap through the aggregate ports.

[FURRYe38]

What Firmware version is currently loaded?

Is LAG enabled on the modem? 

Does this happen if you disable LAG on the modem?