Problems with stair behavior (Spruce Stairs) when using for roofing.

Wooden stair blocks (spruce) have erratic behavior when in proximity to other stair blocks. I could not follow roof outline, as stairs refused to set properly. Issue occurred when creating inside curve next to tight outside curve. Behavior either continually tried to take a shortcut and bypass the outside curve, or, block assumed incorrect shape. Attempted roof was geometrically consistent; however, it could not be completed. World was in Minecraft Realms. Two participating players had same issue. Attempted to exit server and re-enter to clear, with no success.