Rhino DXF import skipped a repeated vertex in a self-retracing LWPOLYLINE, so a horizontal edge disappeared and a new diagonal appeared. AutoCAD and Illustrator open the same file correctly, silently changing laser-cut geometry.
From the Grok pain-radar digests, Oct 26-27 2026 (Oct 26 12:41 PM ET through Oct 27 7:41 AM ET digests plus the Haitch editions). Verified live 2026-10-27: issue/PR/thread read; title and state confirmed.