Missing/broken materials on geometry blocks when alt-dragging

I have a multiplayer map that I am designing for school. I have been working on this project for a couple of weeks, but now whenever I try copying a geometry block i.e. stairs, if it is overlapping an object, parts of the stairs and the other object will disappear. It still has a material and everything, but is transparent in certain spots.

How do I fix this? I can provide pics or whatever else.

Hello,

We’ve recently made a switch to a new bug reporting method using a more structured form. Please visit the link below for more details and report the issue using the new Bug Submission Form. Feel free to continue to use this thread for community discussion around the issue.

https://forums.unrealengine.com/unreal-engine/announcements-and-releases/1410408-unreal-engine-bug-submission-form

Thanks