Disappearing simple lights - US Pure

US Pure.

A player has put simple lights up in his heli tower and they seem to be despawning.

They are placed in the middle of his tower along the wall frames. He does have an elevator in the center of the build where the lights are as well. (see pictures) 

It also appears that the lights half clip through the floor. I don't know if this could also be a reason for them disappearing. I have informed the player to move them to another frame to eliminate the elevator being the cause of them disappearing as well as placing them on a wall to eliminate them from half clipping through the floors to see if they disappear on him after doing that.  He will be putting in a help ticket for replacement simple lights after he counts how many have vanished.