A good flashlight and mirror will let you know if the stud is broken(unless your doghouse only has a small access panel, you should be able to do the inspection from the top...doghouse removed).
As the engine heats up around the stud, it may have vibrated out...here's hope'n. If the stud is broken, it sometimes can be pilot holed and taken out with an ez out. If the stud is in a difficult position, well, that can get a little expensive. At any rate, the leak can only get worse...IMO, you should get it taken care of.
Jan and Bob