Alright, since the forums won’t let me create a new post, I’ll add mine here.
It’s not the “spot” that causes this to occur, but the circumstances behind it. Basically, the game works on a pseudo 3-D setting. 2-D is the standard movement access we have in game. The 3rd D comes into jumping around which temporarily heightens the character’s z-axis so to speak. You see this in use a lot on certain skills that high a large aoe but small z, so that you can jump over them.
The bug enters here: Normally, when you jump, you will quickly reenter the correct Z-axis for your location (ground). But there are instances where your character breaks the typical ground z-axis and sets a new ground. This is what is occurring in several of your statements. For the house, you somehow clipped into the house a bit, and that reset your axis. For bosses, if you move into the same X-Y location at the same time they do, it causes you to share the same spot, so the only fix is to shunt either you or their Z-axis to a new location. I’m not entirely sure how it works for the card battle, but it’s probably a loading issue.
Now the problem here is that your character has entered a very strange Z-axis that is not the norm. When you jump and do not move your XY axis point first, the game registers you at an unknown Z-axis and doesn’t know where to place you, so when you go to land, it sets your Z-axis at the highest point (or close to it) that you achieved.
I’ve noted the glitch a few times and was coming to the forums to comment on it. The best places to see this are during boss fights especially melee bosses (they are large enough to break the Z-axis) and during cryomancers Ice Wall. The reason mobs don’t get stuck with Ice wall is that they cannot jump and move in the X-Y axis before shifting Z. This fixes their location, but yes, I suspect that if the mobs jumped, it would cause them to get stuck in the sky as well. So, go pvp some cryomancers and see if you can get this to occur as I suspect it will.