I had the same issue. For me this happened after I renamed my app and changed the package name. I did not do this properly for android.
After following this guide of how to change the package name, things worked fine for android.
Make sure the package name in AndroidManifest.xml and android/app/build.gradle and android/app/src/.../MainActivity.java is the same. Also check ios/Runner/Info.plist the value of CFBundleName for iOS versions.