Cordova - Load External URL content in app takes too much time

I have one cordova app that loads content directly from client website.I have used it like <content src="https://example.com/ios/index.html"> in config.xml file.I have used the splashscreen delay of 6 seconds.and the issue is when the splash screen hides shows the black screen for 5-10 seconds and after that client website content is shown.and also sometimes i am getting the error CONNECTION TO SERVER WAS UNSUCCESSFULL.I have also specified <preference name="loadUrlTimeoutValue" value="700000" /> but still having same issue.Anyone having the same issue for cordova ios and android app?can anyone help me with this issue.