Internal network loses connectivity if internet goes down

[searay268]

We have a Nighthawk Mesh WiFi 6 (MR60) system with one MR60 and two MS60 satellites running firmware version V1.1.7.134.

We have numerous wireless devices in our home such as smart TV, Roku devices, phones, tablet, printer and of course computers.

Everything is great as long as the internet is up but if we lose our internet connection, the devices connected to the Nighthawk network lose connectivity.  Now, I understand I cannot get out onto the internet but I do not understand why my internal devices connected to what I call the same network lose connectivity with each other.

For instance, I use one computer with multiple displays to remote desktop onto another windows laptop.  Everything is fine until my internet goes down.  At that point, I lose connection to the remote desktop session on the laptop and as far as I'm concerned, losing the internet connection should not interfere with the connection between those two computers.

Any idea?

Thanks

[FURRYe38]

Ya that shouldn't happen. Everything LAN side should will work if the WAN side doesn't get internet services. 

What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?
Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended. 

So this happens if you turn OFF the MS and just have the MR running and a couple of LAN devices connected to the back of the MR, emulate disconnecting the ISP modem from the MR and connections between the LAN devices stops? 

Any feature services enabled like IPv6, Armor, or SPC on the MR? 

[searay268]

I'll have to try the test you're suggesting; however, I can say IPv6 and Armour are disabled.  Not certain what SPC is.

As far as the test you suggest, it sounds like you are saying to turn off the satellites and connect devices via cables on the MR, don't use WiFi.  Is that correct?

[FURRYe38]

No, just wondering if you do turn OFF the MS and then connect ethernet to the MR. Then disconnect the MR from the ISP modem, do the ethernet connected devices still get an IP address and able to see each other. Reconnect the MR to the ISP modem after trying this quick test. 

SPC is Smart Parental Controls. Maybe seen on the Nighthawk app.