I have a mesh system consisting of three DECO X50 PoE. For six months it worked flawlessly, but suddenly the internet connection performs really bad and unpredictable.

Webpages fail to load, my job applications (Eikon, teams etc) cant connect, streaming services fail to work. Intenet connection is not completely lost - pinging servers works although most other traffic is not working. Certain webpages like google.com works although most other webpages fail to load. (strange!)

The problem is in the router, not the wifi, as it persists when I connect with cable. Bypassing the router and connecting with cable directly to the fiber modem always work without problems.

I have upgraded to latest firmware. I have changed dns-servers to 8.8.8.8 and 8.8.4.4

What can be the problem? What can I do to troubleshoot?

regards

Adam