After learning that 20x25x4 aren't all the same size, I ordered the actual size written on the old filter. The replacment fit exactly for a much lower cost.
The filter doesn't fit by about 1/8th of an inch. I had to scrunch it up a bit to finally get it in. It's going to be hard to get out. I don't know how that can be fixed for the future. Let me know what you think. I may want to cancel my automatic deliveries. Will let you know.