@DanielGB 

First, please update the driver of the wireless adapter on your computer for the 802.11ax router. Below is the instruction: 

https://www.tp-link.com/support/faq/2303/

What about other wireless devices? Do they work properly? 

Cause it supports 2.4GHz only, please ensure that the smart connect is disabled; and please ensure that the firmware is up  to date. 

Besides, you can use channel 1, 6 and 11 for 2.4GHz and channel width 20MHz to give it a go. 

Any updates, please let us know. 

@Kevin_Z 

I do not have problem with other devices (iphone8, pixel3, ipad).

smart connect is disabled for sure; and it is running the latest firmware available at US support web page.

No success when I change these options ( you can use channel 1, 6 and 11 for 2.4GHz and channel width 20MHz to give it a go )

I forgot to say that my laptop is running ubuntu 18.04. I also tried other linux flavors (Mint 18 and Ubuntu 19.10) but the connection keeps dropping out.

I keep searching a solution...maybe it is a linux/kernel/module issue.

I accept suggestions.

@DanielGB 

Thanks for your reply. 

Cause other devices work properly and different linux flavors have the same issue, I'm afraid that it has something to do with the laptop itself. 

Have you ever tried to update the driver for your linux PC?

Besides, you can reserve an IP for the linux PC on the web UI of the Archer AX50 to give it a go. 

Good day. 

@Kevin_Z 

My laptop was working fine with my previous router. When I'm out of home I connect to free hotspots and I don't have problems as well. 

I just lose my connection at home when I use Archer AX50

@DanielGB 

Thanks for your reply, cause the linux PC supports 2.4GHz only and the Archer AX50 is a new product with new technology; it seems that the capacity of the wireless adapter on the adapter is not powerful enough; 

You can change another adapter to give it a go. 

May it help.