As Pecos said, do some measuring and see if it is just memory or design. If all of the walls are the same height, it is memory. If the walls in that corner are shorter, it is by design. Assuming it's memory, then move it along with some pressure, "the come along". Since it is still in the "move" condition, consider a compactor
. One that will adjust form low vibration up and run it from room to room. Letting it sit is essentially time and normal activity wiggling everything into place. Accelerate the wiggling and shorten the time.
OR, if you choose to pull it down, run a cable or two up through the floor to a new cross beam in the attic, so you will be pulling down on the entire wall assembly. That will help hold things together. Of course once you get it down that way, you still have to consider what will happen once you release the tension on the cable. You may have to leave a cable in place inside a wall.
Shake it down,
Bud