Run Time Error on Real Android Device

I have an Ionic 4 app which has the php(mySql) as a backend. App working fine with ionic serve --lab(using CORS extension) but when i build this app with ionic cordova build android, .apk file installs and open its static pages correctly but when i click on any of the component which accesses the server it doesn’t work then. Why this is happening? How to debug then? Plz help

Hello, Inspect your device using chrome inspect, see there what is error?