Hello davide9292, if your router can do 5GHz, choose the 5GHz ! Modern DSL router e.g. AVM FritzBox 7590. It offers many functions and fast WLAN, is well prepared for the future as it can handle Supervectoring 35b for fast DSL, or a DSL box with the new WLAN standard Wifi 6 (WLAN-ax).

I don't know, because I'm connected to 4G