After build lightning and restarted editor the foliage is still dark in lit places

I have a problem with vegetation lightmap.
When I build the lights on the vegetation in the editor everything is ok until I restart the editor.
After restarting editor my vegetation is still being lit by skylight but in lit places have color identical to the skylight. The problem disappears after running the game - the vegetation has a proper lightmap. My second lightmap UV on vegetation is fine. This problem occurs in all types of vegetation.

Thanks for help.