installed AC750 EX 3110 as extender to a router by the phone provider Fastweb (Italy)

[Fabio26]

After installation got good communication to router by WPS and 2 wifi networg names with right extension ; trying to connect devices, says that password is wrong;

But shoud be the same as for the original router

Am I missing something?

[plemans]

Did you set it up using the push button WPS option? 

If so, factory reset the extender  and set it up using the installation assistant.

To factory reset, push and hold the reset button for 7-15 seconds while powered on. 

Here's a video of how to use the assistant. 

https://www.youtube.com/watch?v=yJVklshxBMk