NewPingESP8266 server not returning a distance reading

Question

I am currently working on a small at home projecting involving a WeMos D1 Mini and an HC-SR05 ultrasound distance sensor. This is currently running a server which, on request, should return the distance between the sensor and whatever is close to it. I know for a fact the server works as the test function returns 6 without issue, but I cannot get a proper reading from the sensor. Are there any obvious issues with my code that I have missed? I know that NewPingESP8266 does not officially support the HC-SR05 but I see no real reason it should not work as its practically identical to the supported HC-SR04. Here is my code, thanks in advance!

    #include <NewPingESP8266.h>
    #include <ESP8266WiFi.h>
    #include <ESPAsyncWebSrv.h>

    const char* ssid = "Distance sensor";
    const char* password = "123456789";

    NewPingESP8266 sonar(14, 12, 450); // replace 12 and 11 with actual pins



    String readDist() {
      String distance = String(sonar.ping());
      Serial.println(distance);
      return distance;
    }

    String TestFunc() {
      return String(3+3);
    }



    IPAddress local_ip(192,168,1,1);
    IPAddress gateway(192,168,1,1);
    IPAddress subnet(255,255,255,0);

    AsyncWebServer server(80);

    void setup() {
      pinMode(14, OUTPUT);
      pinMode(12, INPUT);
      Serial.begin(115200);
      WiFi.softAP(ssid, password);
      WiFi.softAPConfig(local_ip, gateway, subnet);

      server.on("/distance", HTTP_GET, [](AsyncWebServerRequest *request) {
        request->send_P(200, "text/plain", readDist().c_str());
      });
      server.on("/test", HTTP_GET, [](AsyncWebServerRequest *request) {
        request->send_P(200, "text/plain", TestFunc().c_str());
      });
      server.begin();
      delay(1000);
      Serial.println(readDist());
    }

    void loop() {

    }

When trying to use the distance function, it thinks for considerably longer than the test function, but returns 0.