It looks like I have reduced it to just 2 files. I'll upload them presently.
So in the ep file, look for P-EP25, and adjust the offset of the narrower end to match the adjacent EP line. I find that it has something to do with preprocessing some information about the linework. For certain linework it always seems to unsnap. For other linework it behaves fine. Repeatability may depend on toggling live attachments on and off, from my experience.