In this forum post you can learn how to debug phonegap builds: https://forum.mendix.com/link/questions/14222
Regards,
Ronald
If the app is failing to load it is usually to a bad widget included in the app. You will probably need to debug using something like winre or phonegap debug tools to see if there is a javascript error. Infinite loading screen usually suggests a javascript widget issue.
You will only have an issue with certificates when building the app in phonegap or when installing it on your device. Since you have been able to do that we can rule out certificate issues.