I believe this might be an issue with your model, I may be wrong but looking at it The only model with the issue seems to be the one it is coming from, Alternatively You could add a different rotation to your directional light though I feel this might ruin the whole look of your game a bit.
Many years later now, and I ran into this same issue. In my case, the problem was that the floor itself was supposed to be casting the shadow which would cover up the shadow of the dynamic object. This is probably the line of investigation you should go down.
There are many reasons why this may be happening, but in my case it’s because the floor was a static object whose shadow was cast using the lightmapper, while the dynamic object’s shadow was… Realtime (i.e. Lighting Mode: Subtractive).
The lightmapped shadow coupled with the floor’s lightmap resolution being too low to display a proper shadow caused the dynamic shadows to show up where the floor’s shadow should be instead. Once I had the static object’s shadow properly cast, this was no longer a problem
