As shows your App from screenshot and any “ARFCN Calculator Online” on the internet, this NR-ARFCN 634080 is equal to 3511.2 MHz frequency that is in range 3500 - 3600 MHz. Everything is correct from this point of view. Nevertheless I can’t confirm that this NR-ARFCN should be used in your network, because I don’t know what NR-ARFCNs your operator is using