@Supremo is the 5ghz on 80mhz or 160 mhz? Try 80 if on 160. 

  @wesselkoning 

Yes, I tried, with no success

wesselkoning wrote

  @Supremo is the 5ghz on 80mhz or 160 mhz? Try 80 if on 160. 

  @David-TP 

Yes. The same result

  @Supremo 

I have discovered that if I put it in Access Point mode, deactivate the 5Ghz and 80 Mhz bandwidth, it does add them, and they work. But then it is the carrier router (very bad) that works, which is not what I want.

If I put it in router mode, managing only the data VLAN, it stops working. They continue to appear in the Smart Life application, but they do not connect or give alerts. And if I delete them, in router mode I cannot add them.

The rest of the IoT devices work perfectly, I just have to keep my SSID and password in all cases.

  @Supremo

I hope that you were able to solve your problems because I am waiting to receive a set of two new Deco X75 Pro, after having tested a X50

and I am affraided, as in your case, my IoT problem is not going to be solved do to the fact that both software are the same. If that is the

case it is a pitty because otherwise the routers function well, but in that case I have to go somewhere else. I am/was expecting a better

response from AI TP-link routers in this regard, and after using an excellent set of Taotronics mesh routers during several years.