Maps are enclosed entities in apps, and that causes all of them to appear black on a screenshot by default . That's just how your device works.
Shake constantly works on custom upgrades
We've invested a lot of time to support:
Google Maps
OpenStreetMap
so these popular maps won't appear black in your bug reports. If your map is black and and you know which map type your app uses — email us at friends@shakebugs.com 📬 to let us know that you want us to develop support for it too.