@David-TP Thank you for replying to my message. 

These are the maps or topology of my network at home. I usually have problems only on mobile phones. To be more precise with the youtube app, to be more specific with the YouTube shorts. 

I have already tried many suggestions, change the DNS of the operator to those of Google, I also changed the random Mac in the WiFi settings of the mobile phone. Also turn off the mesh, fast roaming and Beamforming. And it's annoying because I'm close to the main modem and it's still given me problems. 

  @David-TP 

1) Well, I have 4 DECO xe75 pro, I have made changes to see if any of them gave problems and it just so happens that before I had two models I have problems now with two more I still have them. 

2) YouTube shorts when passing one after the other, it does not load and take time to play, sometimes I am watching a short and it stops to load and takes its time. 

3) The phone models are 2 galaxy s24 ultra, a galaxy S21, a galaxy A13. 

As far as the bands are concerned. I isolated the 6GHz band to see if it was the problem and it didn't work, I also disabled the 6GHz band and I had those issues as well. 

4) I have done the mobile data test, I have disabled the WiFi and I have used mobile data and in mobile data I do not have those problems. 

5) I think it's the deco because I've turned off the mesh network of the operator's modem and with the operator's model I don't have any problem. I must clarify something very important. In the frustration of not knowing how to solve the problem I had to change Internet operator (Proximus) to see if it was a problem of the previous operator (Orange) but even so the problem persists and it was at that moment that I took for granted that the problem was the DECO. 

Thank you very much for your answers and your time.