Build --prod and HTTP

Which is the difference between building with --prod flag and without?

I have a simple app to send a post to the onesignal service, using HTTP (cordova-plugin-advanced-http).

It works well with ionic cordova run android --dev.
So I run ionic cordova build android --prod and send the apk to a device. It run but does not post anything (the http post has an error undefined). After a while and many curse, I find out that the apk built with

ionic cordova build android

is OK! I retry ionic cordova run android --dev and this one does not work.