Export issue: Part of wall disappeared

Simple room. Wall was built with a continous line, starting north side just west of door, going clockwise, ending northwest same spot as beginning. Exported as layers. A small bit of the southern wall disappeared during export. This bug is reproducible for this map, built today with latest update. I also emailed this report with a screenshot, as I don't have photos stored on an external site. Will add them if site allows uploads from camera roll.