Question Wi-Fi network constant drop outs

[coder_mkd]

Hello, as I can see there is similar threads like this but none of them solved my problem.

I have constant disconnects from the wi-fi network and when troubleshooting the problem, windows give me Unable to resolve DNS address, or Cannot reach DNS server.

Router: ZTE Speedport Entry 2i , the distance is ~7-8 metres with wall between, I also have Tenda A9 n300 extender which is right bellow me.
I'm getting excellent signal and around -38dB signal strength.

At first I thought it might be the Wi-Fi adapter problem, I have TP-Link wn881nd with dual antennas, and now I replaced it with my old Tenda USB wi-fi adapter but the problem persist.

Tried all fixes like ipconfig /dnsflush, /release, /renew, but its all the same, and actually last night when doing this, I lost internet with error Cannot contact DHCP server, the IP address that was assigned was starting with 169.xxx.xx.xxx and I've had no connectivity at all, I tried connecting with mobile device (iPhone 8 plus) and the same problem was on my mobile device too until I disconnect the power of the router, so I assume its router related problem. Most of the time this problem is resolved with reconnect on the network, but sometimes it keeps going for like 5-6 times in a row and its really frustrating. Also I have spikes during conference calls and gaming (latency).

I've contacted my ISP, they came to my home but everything was fine, speed good, cables good. I've also changed routers channel to 11, because there wasnt network on that channel.

Also during this problem, the router is unreachable by ip address

 

[Ralston18]

169.x.x.x. is an IP address that Windows assigns itself when it cannot find a network connection.

How tightly is that extender fitting into the wall outlet? Try using an extension cord to raise the extender up and about - may just need a few feet of relocation to establish and maintain stronger signals. Especially TX.

Also check that no other network adapters are enabled on your computer. Only the wireless adapter should be enabled.

And again, you might try using an USB extension cable to raise the USB wireless adapter up and away.

When the computer has been off for while touch the USB adapter - should be room temperature or so. Then after the computer has been on and hopefully even connected to the network carefully touch the wireless USB adapter. It should be warm but might be quite hot. In which case the USB wireless adapter may be the problem. Or with two affected wireless adapters - USB port problem perhaps....

 

[coder_mkd]

To be honest its not really tight into the wall outlet, but when the problem occurs, I can access the extender via IP address, but not the router. Also when this no connectivity occurs, there is no internet on any other device (mobile)

Edit: Strange thing, now I was on a zoom call, the call was all fine, but I cant open any web page, when troubleshooting I'm getting error The DNS server isnt responding

Edit2: Also when trying ipconfig /renew, I'm getting error:
An error occurred while renewing interface Wi-Fi : unable to contact your DHCP server. Request has timed out.

UPDATE: Removed the extender entirely, now I'm getting stable internet, with -39-47 dB signal strength with the USB wi-fi adapter, I switched also to TP-Link wn881nd PCI with dual antennas, I'm getting -80 dB signal.