Hey guys a combination of 2 awnsers solved my problem. It was port related.
adb reverse tcp:8088 tcp:8088
react-native run-android --port=8088
By doing this, the app loaded fine of my phone connected by USB. I think my AV or Vagrant or something elses in my PC was using that port.
You can change 8088 to something else if needed.
Enjoy!