R7000P - network disconnected

Hi,

about a month ago, my router R7000P was giving me weird symtomps. Whenever my laptop connected to 5G, it would make ALL my other devices that connect to 5G disconnected (or maybe I should say that the 5G wifi down). It would be about 3-5 secs, and then it would up again and all devices can reconnected again.

ok, I dont know what's wrong and I blame it all to my laptop. from then on I'd only let my laptop connected to 2.4G network.

But about 2 weeks ago, the router started a new symptoms. It would randomly disconnected ALL my network. Yes, All. All wifi down, and even lan cable network down. It is like once in about 20-40 mins. So annoying. And no, this have no connection with the laptop anymore as this happened randomly even when my laptop is turned off (yes, means it was shutdown and not sleep, so it wouldnt be possibly connected to the router and affected it in anyway).

I have tried updating the firmware to the newest (firmware version V1.3.2.134_10.1.66), I have tried to disable mumimo, enable dynamic qos (that I never used before, and I still dont know what it is for). All proved useless.

At last I factory reset it yesterday, and today, it's still the same, no improvement.

Now, one thing that ticks me off. Every time it disconnected about 3-5 seconds, and connected again, since a few days ago, I tried to see the logs. And every time, the logs would be cut off, which means there would only logs started from the time it was disconnected. There was no logs prior it. Why is that ? My idea is that the router might be restarting when it was disconnected, so the logs were automatically cleared. Is it right ? would the logs cleared itself when restarted ?

I never able to see the router when it disconnected because I always late in remembering having to run to the router place when it disconnected, because it only happened about 3-5 secs, and all connected again, so I wouldnt know if it restarted in the time.

would anyone have more ideas to try ? because if can, I dont want to send this router to netgear technician, because it would mean my house's network would down for a few days.

thx