As of 4.11.2, the box primitive static mesh does not seem to be able to generate distance fields correctly. I noted that there were some serious shadowing errors in my maps after upgrading my project to 4.11.2, and it seems isolated to distance field generation on this static mesh:
This static mesh is the cube primitive packaged with the engine. No modifications have been made. If I pull in a fresh copy of the static mesh as a static mesh actor, it shows the same results. As you can see in the debug view, the distance fields are generating some seriously garbled geo. Any idea what might cause this?