Hi Makotech222,
I’ve reported this issue with UE-11026. When I tested this I tested with 4.6, 4.7, and our internal build of what will become 4.8. This was happening in all three and is not isolated to being an issue directly related to 4.7. I was able to see that using stationary lights cause clipping artifacts. If the directional was made to be movable from stationary it would lose all shadows. When going back to stationary these shadows would remain removed until lighting was rebuilt.
Here is the video of my results with testing in 4.6: Dropbox - Error
Thanks again for reporting and I will update once the ticket has been resolved, however there is no ETA for when this will be assessed by an engineer.
Tim