Project is fetching data when in "ionic serve", but doesn't work properly when built as an APK

I have an Ionic Project which has an authentication and simple data fetches on a server. On “ionic serve”, everything works fine - all the requests work. But when I build an APK (doesn’t matter if I use --release).

It will only authenticate and further requests end up on a very long loading screen (it hits timeout) - It doesn’t even reach the server as it doesn’t trigger any back-end log that it entered either the method or controller.

Somewhere, along the way, it does only ONE request (in this case, the ‘authenticate()’ and then nothing beyond this point.

We believe that these requests are being ‘killed’ right away on the cellphone.

Could it be permissions? Is it because of our HTTPS server?