WiFi Router keeps refusing connection until reboot

[wingl]

I have a Netgear Nighthawk DST AC1900 router that was working fine for about a year until about 2 months ago. I love the performance of the router so I'd like to stick with it if possible. Since the last firmware upgrade (or about then), the router works fine but after about 5 hours of up time, it will drop 5G and 2.4G connections. The 2.4 will come back for some devices and allow re connection but the 5G will get stuck at connecting and never authenticate. Some devices reconnect perfectly while others cannot. If I reboot the router, all is well and everything is working again. So obviously, it's the firmware, so I revert back to the previous firmware and it's the same thing. So the next obvious thing is the router is flaky. I go and purchase the exact same model and it does the exact same thing. I've checked the channels it's working on and it's all clear.
The next step in troubleshooting is to try a different vendor. I plug in a spare Trendnet AC and it works like a charm. I left it on for about 3 days so I really haven't fully tested it for the long haul. I switch the Nighthawk back and devices drop again.
I'm at my wits end trying to figure out a setting I may have missed. Any tips would be greatly appreciated!

 

[Graybush]

There's three possibilities that come to my mind:

1) There's a hardware issue in the router
2) The router is overheating
3) There's something on the network causing a broadcast storm

Have you tested for these possibilities?

 

[wingl]

There's three possibilities that come to my mind:

1) There's a hardware issue in the router
2) The router is overheating
3) There's something on the network causing a broadcast storm

Have you tested for these possibilities?

 

[wingl]

Thanks for the reply. Just brainstorming here with you, not bashing your answers.

1. Don't think it's a hardware issue unless it's in the model itself since I already swapped it out for a brand new one.
2. The router is in a room that is not excessively warm, about 70F. The case itself doesn't feel any warmer than the Linksys and FIOS router I have in the same room. In fact it's cooler than the FIOS by a noticeable difference.
3. If that's the case, the router itself would be blitzed and the 2.4 wouldn't work at all. The wired connections always work so if it were a loop or DOS type of hit, the wired would also be affected, right?

This is why I'm stumped.

 

[Graybush]

Thanks for the reply. Just brainstorming here with you, not bashing your answers.

1. Don't think it's a hardware issue unless it's in the model itself since I already swapped it out for a brand new one.
2. The router is in a room that is not excessively warm, about 70F. The case itself doesn't feel any warmer than the Linksys and FIOS router I have in the same room. In fact it's cooler than the FIOS by a noticeable difference.
3. If that's the case, the router itself would be blitzed and the 2.4 wouldn't work at all. The wired connections always work so if it were a loop or DOS type of hit, the wired would also be affected, right?

This is why I'm stumped.

It might not be the router, but your ISP acting up then? If it's not the hardware, then it's probably the software.