Not to be a downer but it looks like you didn't put any solid blocking under the legs of the pool.
The legs of the pool bear the weight of water pushing on the walls and when the pool is full that's a fairly significant weight. The weight of the water is driving the legs into the ground from the looks of your photos.
Typically when setting up the pool you place concrete blocks under each leg to stop the legs from doing what your photos show they are doing. The concrete spreads the force of the leg out over a larger area which stops it from being driven into the ground.
When setting the blocks you should dig out just enough dirt so the top of the concrete is flush with the surface of the dirt. You should try and get the top of each block the same exact height. You are shooting for less than 1" difference in height from one side of the pool to the other.
The only safe way to get blocks under your support legs is to drain the water out of the pool.