RAX75 randomly loses internet for some devices after firmware upgrade to 1.0.10.140_1.0.79

[albertw]

After finishing firmware upgrade through the Nighthawk app to 1.0.10.140_1.0.79, some devices start to lose internet random from near immediately to after some hours.  It looks like a combination of rebooting the device or power off and on the router would restore the connections.  My RAX75 router also has the auto firmware update enabled.  But i did not take note of what was the last firmware version installed.  And the latest 1.0.10.140 version was obviously not auto-installed.  As such, I would like to see if someone has experienced this and how to address it?   I think I would observe for another day or so, and see if it makes sense to risk downgrading to the previous 1.0.5 or 1.0.6 version.

[microchip8]

First, disable auto-update of firmware. It can brick your router.
Second, don't do updates through apps/wifi. Use a wired connection and a PC.
Third, have you done a factory reset and reconfigure from scratch?

[albertw]

Thanks for your recommendation.  I will try to disable the auto update for now.  Meanwhile, as my router is directly connected to my cable modem, I would expect the firmware update would have been performed over the wire only (and since also I connect the device from the Nighthawk app from anywhere as well, hence no wifi connectivity was involved in for that. But I could be wrong).  And I have had my router for just 3 years without an issue, I haven't tried any factory reset so far.  But I think I would consider that route when the random loss of internet happens again next time.

[FURRYe38]

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. 

Recommend setting the default DHCP IP address pool range to the following after applying and a factory reset: 192.168.#.100 to 192.168.#.200

What all devices do you have connected to the router? 

How do you have Basic and Advanced Wifi settings configured on the router? 

What is the size of your home? Sq Ft?

What channels are you using? Auto? Try setting manual channel 1, 6 or 11 on 2.4Ghz and 40 to 48 channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?

Is Armor, SPC or Traffic Meter ever been enabled? 

Try enabling Beamforming and MIMO(MIMO may or may not be needed) and WMM. Set 20/40Mhz Coexistence to 40Mhz only. Under Advanced Tab/Advanced Settings/Wireless Settings