MapBox div is displaced after opening modal in another view

Greetings. We are building an app using MapBox and Ionic. We have an issue with the MapBox div getting displaced after opening a modal in another view.

Steps to reproduce:
(The app is in Danish language.)

  1. Go to a demo of the app here:
  2. View in device mode i.e. iPhone 6.
  3. See that the MapBox map loads.
  4. Click on the Feed tab.
  5. Click the plus sign in the top right corner.
  6. Click “Luk” in the top right corner to close the modal.
  7. Click on the Kort tab, to go back to the map.
    Res: The MapBox div is now displaced and unusable.

Why is the modal causing this when it’s two different views? Is there another fix for it? The code is available here:

Is this perhaps a MapBox issue?