If you add the compass (both - the orienteering compass, or metal one) to the hot bar (in the bottom of the screen) then take it out of your hands to the inventory, its needle shifts by 90 degrees CCW. So, If you look at north, needle will point to the west on the hot bar icon (if compass is stowed away). If you hold it in your hands everything works fine (hot bar icon fits the item in your hands). It would be better if hot bar compass also shows actual heading even if it is in your backpack. Please fix it with the upcoming update!