Here is a video explaining how the folding assembly lock has changed from the V1 to the V1.5 and V2 Burn-E and the cause of the misalignment issue where the threads will not engage.
https://drive.google.com/open?id=1ig4IGdM9MLbuvm6nDlGGRJJ9BZ6d9ba6
Nami Burn-E Folding Lock Revisions and Misalignment Issue
I have this issue it will not tighten up for me.