Casting realtime shadows on lightmapped objects

I have a scene with some static objects, and some dynamic objects. The static objects are lightmapped, and although they have lightmapped shadows, they’ll cast realtime shadows on dynamic objects as well. This is good, however, it doesn’t work the other way around. The dynamic objects cast no realtime shadow on static objects in deferred rendering, and cast ugly pitch black shadows in forward rendering. What is the problem and how do I fix it?

Try setting the lightmap settings on the light you want to use to cast the realtime shadow on the lightmapped object on ‘RealtimeOnly’. This is the only way I’ve figured out to cast shadows on baked objects so far.