Is this a bug report?

Yes. I have also seen this issue on stackoverflow.

Have you read the Contributing Guidelines?

Yes

Environment

1. react-native -v: 2.0.1
2. node -v: v8.0.0
3. npm -v: 5.0.0
4. yarn --version: 0.24.5

• Target Platform: Android
• Development Operating System: macOS
• Build tools: N/A

Steps to Reproduce

Using the Picker component in Android, the first onValueChange fires, but the next one does not. The one after does...this continues and results in about 33% of the time onValueChange does not fire.

I created a snack with a basic example.

Expected Behavior

I expected onValueChange to fire if the Picker item selected is different from the current selection.

Actual Behavior

About 33% of the time onValueChange will not fire, but the text on the Picker does change, which is confusing to the user. The other times, everything works as expected.

Reproducible Demo

I created a snack with a basic example. Select one option, then another and, in my experience, it will not consistently log to console.