@Solla-topee 

hello, first of all thank you for replying 

As for the old router RE200, the problem was different, it did not show the wi fi network, it allowed it to be reset

Instead, as regards the current router, it is a RE190, v.5 with updated firmware. I do not know the details of the main router, as it belongs to the owner (with his consent), but I believe it is a Vodafone station with optical fiber

The LEDs all remain on even when it is not working, but since the internet does not work, it does not allow me to access the control panel of the router. I then have to unplug it to resume

The only red light is that of the location, as it is a bit distant, but I don't think that's the problem because the old router also had the same location and worked, and this works occasionally

At the moment, it only worked for two days by putting these settings:

1)LAN auto

2) DHCP off

3) High Speed mode auto

This morning after two days without problems it started not working again until after I disconnected it from the current

The other alternatives I've used are:

1)LAN Manual with IP address and gateway of the main router; and DHCP on configured similarly - No positive result

2)LAN auto and DHCP manual, So it worked for almost a week without any problems, and then went back to not working

3) even the reset did not lead to any solution

So I don't understand if it is a problem of wrong settings or lack of compatibility with the main router (but in this case it would not explain why the old one worked)

Thanks in advance for the answer, if you need anything else ask

I am also willing to speak to an Italian technician to resolve the problem