I have been getting this happening in the same spot, twice. It is a top layer that is set to 2, i usually like 3 but filament restrictions on consumption didnt allow for it. This has been a wierd model to work with, not my creation, and there is bridge infill underneath this layer. Temps are 240 and 80, layer height is .45 with a .6 nozzle. The floor is for some reason divided into 2 parts left and right. The other side printed good.