I made a short video explaining it much better → Unreal Engine: Procedural Mesh Bug Report. - YouTube
But basically, the collision on the procedural mesh breaks whenever you use copy/duplicate to make another ‘Add Procedural Mesh Node’. But just watch the video. Easier to understand. ;D
If you want system specs or like ‘steps I took’ just ask me. The bug is pretty straight forward though. And well hidden 
A friend of mine told me to come here and upvote this. I watched the video. I don’t approve of anything being broken, so it wins an upvote.
Hello Rainbow.Warrior,
I was able to reproduce this issue on our end. I have written up a report and I have submitted it to the developers for further consideration. I have provided a link to the public tracker. Please feel free to use the link provided for future updates.
LinkL Unreal Engine Issues and Bug Tracker (UE-45019)
Make it a great day
This issue still persists in as latest as 4.20. It has only 2 votes on the issue tracker (mine’s the second one), but is there any way this can be fixed? I just spent two weeks banging my skull and it turned out to be a bug in UE itself! Wouldn’t want this to happen to anyone else. 
Thanks for the tip man, I was getting crazy ^^’…