When a PaperTileMapComponent is generated at runtime, the collision that it should have is not generated along with it. This can (oddly) be remedied by selecting the component itself in the details panel, at which time the collision will generate.
Project: [Link Removed]
To have it work:
After pressing play, hit Shift+F1, select the BP_TileMaker blueprint in the World Outline and then select each one of the BP_TileMaker's PaperTileMapComponents. After doing this, they will have collision.
Head over to the existingAnswerHub thread and let us know what's up.