Certain BP class properties keep losing value

Hi everyone. I found this problem too on 4.13. It’s totaly mess and lost of time. I’ve discribed it here in contex of location loosinganswers.unrealengine.com/questions/499077/random-actor-lost-location.html
and hereanswers.unrealengine.com/questions/499479/actors-losing-map-location-after-compile-realy-ama.html

Since two months I’m trying to understand this, to make better bug report but with no result. This issue occurs on realy simple basic c++ and BP actors. There’s nothing problematic in code.
Unreal, please help. This is realy serious problem and my work with this is realy hard if even posible.