[Please help]Same code but doesn't work on server

I copied encryption code from jadx-gui and place for my own java class.
The result of my code is the same pattern as the orignal apk
but mine doesn’t work on their server

There is no api call when encryption.All encryption was in mobile.

The questions

1. It is because I used same code from jadx?
2. Can api request hide from mitmproxy?

Thank you very much.