Source map line number is shifted

This produces at least on Android

I am generating source maps but adding extra packager args in my `build.gradle` like this
```
project.ext.react = [
extraPackagerArgs: isCiBuilding
? ["--sourcemap-output", "pathtoMyFolder/index.android.bundle.map"]
: []
]
```

After that I just upload that source map file to Bugsnag which is my crashreporter. The crash gives me right file .tsx extension but the line is wrong.

Can you help me to solve this? How to start debugging this? Do I have to pass some arguments to transformer or something?