Weird Particle Collision Issue

Hi;
I am trying to do blood decal in my project (from this tutorial). I do everything in the tutorial but particle collisions not work. The wierd thing is when i change view mode to wireframe, particle collisions work fine but when i change the viewmode lit again they dont work again.

[Here is a video about the issue][1]

https://forums.unrealengine.com/filedata/fetch?id=1432802

https://forums.unrealengine.com/filedata/fetch?id=1432801

https://forums.unrealengine.com/filedata/fetch?id=1432803