NEHotspotNetwork fetchCurrent signalStrength always return zero

When I call fetchCurrent on NEHotspotNetwork, I am able to correctly retrieve the SSID and other information, but why do I always receive zero as the signal strength value?

Here my code:

let config = NEHotspotConfiguration(ssid: "mySSID", passphrase: "MyPass", isWEP: false)
            config.joinOnce = true
            NEHotspotConfigurationManager.shared.apply(config) { [weak self] (error) in
                guard let this = self else {
                    print("WiFi network not found")
                    result(false)
                    return
                }
                this.getSSID { (sSSID) -> () in
                    if (error != nil) {
                        if (error?.localizedDescription == "already associated.") {
                            print("Connected to '\(sSSID ?? "<Unknown Network>")'")
                            result(true)
                        } else {
                            print("Not Connected")
                            result(false)
                        }
                    } else if let ssid = sSSID {
                        print("Connected to " + ssid)
                        // ssid check is required because if wifi not found (could not connect) there seems to be no error given
                        result(ssid == sSSID)
                    } else {
                        print("WiFi network not found")
                        result(false)
                    }
                }
            }
        } else {
            print("Not Connected")
            result(nil)
            return
        }

    public func getSSID(result: @escaping (String?) -> ()) {
        if #available(iOS 14.0, *) {
            NEHotspotNetwork.fetchCurrent { currentNetwork in
                result(currentNetwork?.ssid)
            }
        }
    }