I have remarked this strange behavior by infantry when fighting in built up areas: for some reason they will only use the "front entrance" to get into a building.
A section will be positioned at the rear of the building, and ordered to enter it from that side. It may be a few action points away. It will have one or two way-points before the last one right by the building's rear entrance. It will move through those way-points, then, instead of entering the building as ordered, it will go around the whole block, frequently moving into obvious enemy kill zones, while attempting to reach the