Hi and welcome to just answers. I`ll be happy to help you to solve this concern.
the wiper arm assembly has a stop position. to be able to remain down it needs to hit the "stop"bracket otherwise the wipers end up in a deferen position. "like upwards".
sometimes this bracket wich is part of the armature of the wiper assembly bends out and when the wipers try to park they go one half turn over. and end up in the wrong possition. you could try to take the wiper essambly out yourself. and re bent the braket back to the original position wich is alittle triky.
if you like I could give you some gidence in how to do it.