Texture loading bug after build lights in 4.13

Hi all,

After rebuild my lighting in 4.13, my project have these black shadow artifact on my texture. All other projects will have these artifact too, but for a split of a sec when just loaded and everything looks good. This project, however, every time I load this level there is artifact on the texture like this :

but as soon as I touch anything, or just zoom in or out everything the texture reload and everything looks good again like this:

This will not be an issue, but as soon as I clicked on package project, the artifact come back and don’t go away, and the packed project have these artifacts on them. This will not happen if I build light in 4.12 and than merge the map to 4.13. It only happened after I build light in 4.13.
more pictures:

this only happen in 4.13

Did you find a fix for this? I’m having the same problem