Just bumping this in the hope someone has experienced the same.
It is totally ruining my project not having the doors cast shadows from the stationary directional light so really hope there might be a fix and isn’t a bug.
As a side note, to make sure it wasn’t my door mesh, I created a large basic cube, set it to movable (so it could open like a door), and it doesn’t cast a shadow from the stationary directional light either.