Shadow Bugs on baked Lighting Maps

So it’s the first time for me baking light to lightmaps and such. I have previous experience with UE4, but always used dynamic lightning in all of my small scenes.

In a uni course we have to create a scene with baked lighting, so I thought its a good idea to learn. The problem I tho have is, that I receive some weird shadow issues.

As you can see in the picture above, that the shadows don’t match up.
I made sure when creating the UV for the lightmap that it has enough padding.

What I already tried:

  • Have a UV split on those edges
  • Have no UV split on those edges
  • Go crazy with the size of the lightmap (up to 1024²)
  • Go Crazy low (8px)

None of those tries resulted in a “fixed” lightmap. My question now is: What am I doing wrong? I read through the documentation, but cannot find any direct pointers to my problem.
If anyone wants to try out and see what I’ve been doing wrong, here’s the model as an fbx2017
https://dl.dropboxusercontent.com/u/84370332/merrygoround_lightmap.zip

Thanks.