Reproduced with Pixel C with Android 7.0, with Qt 5.9 beta2 package.

Steps:
1. Run the Map Viewer (QML) example
2. Pan around the map with one finger (works)
3. Pinch the map to zoom
4. Try panning around the map with one finger (this no longer works)

The application is still responsive. The sliders on the side still work to change the projection, but the map view itself no longer seems to accept any input.