Hi ,
I’ve setup a similar test scene in 4.4.1 and everything appears to be working fine on my end. I’ve made sure to setup the scene with a lightmass importance volume and also up the lightmap resolution of the landscape from the default 1 to some higher value (something like 4 or 5) for higher quality shadows.
What version of the engine are you using? It’s worth noting that static shadows for foliage was not introduced until the 4.3 release.
Let me know how it turns out. 