Connection keeps dropping. Motorola MB8600 & Asus RT-AX88U

Is this with a WiFi connection ? If so, for a test, does a computer that is hardwired directly to the RT-AX88U router with an ethernet cable have the same problem ?

With this test, we are trying to isolate this from being either a WiFi-only problem or a problem with the general connection to the Comcast system which would of course affect both. It's a good first step of troubleshooting before proceeding any further. 

This impacts wired and wireless connections simultaneously.  When the internet goes down, if connect to xfinity over my mobile data connection, the modem shows fine.  Rebooting the router gets me back online without touching the modem.

For one more test, does a computer that is hardwired directly to the 8600 modem (no router in the mix) do the same thing )?

O/k, oh well. That's an important test because it would isolate it down definitively to either being a problem with the router / your LAN or with the WAN / Comcast system / modem.

So let's try this. What do the modem's signal stats look like ? Try getting them here; http://192.168.100.1  

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

Can not access that IP from this side of the router.  Wife is on a video call now so it will be a while before I can bypass the router.

I seriously doubt it is signal strength.  We were stable for years before we upgraded the router and modem.