Suddenly one day I discovered the answer. In a random video about the intricacies of animation, I noticed that a person’s root bone has Chain. I thought about it and decided to repeat it. Suddenly all my problems disappeared and the animation correctly followed the angles and height of the original animation.
2 days of searching for a problem anywhere, but not where it is needed -_-
I also want to note that the problem of character height needs to be solved in a different way. Although I was able to fix unwanted changes to the animation axis, it did not affect the (location) root. To correct the height, we need to select root in the ik retarget parameters and specify (Translation Mode - Globally Scaled). This parameter is best suited for character skeletons of different sizes, since if we apply (absolute) our model may become deformed.
If you have problems with the skeleton or animations, take a logical approach to solving the problem. I advise you to start looking for the problem from the very beginning, since your settings may be incorrectly configured and all further results may mislead you. As I said, I spent 2 days looking for a problem in BP Character, Anim BP Character in the bones, in the animations themselves, but it turns out that I made a mistake at the very beginning.