Warding Bug

I've noticed in a few games recently that when I walk along the dashed arrow path and try to drop a ward over the wall into the circled bush, that my champion will just walk into the wall and stop. I try again and they don't move until I walk around the edge and place the ward. It doesn't happen in any other bush and I've never noticed it before yesterday. It's happened a few times now. Anyone else see what I am talking about?