The Pearl Abyss game hides a number of mechanics and does not explain them directly, such as additional puzzles in cleared shrines. In the case of the jump, the problem was in the English version of the text. Players complained that the mechanic was unstable and difficult to perform – this was a result of literally following the erroneous instruction.
As noted by a Reddit user, the English description suggests a classic double jump – press the "X" button twice in the air before landing. But the Spanish version explains it more accurately: press "X" just before touching the ground to use the surface as a fulcrum for a repeated jump. Because of this, attempts to jump a second time in the air ended in failure — the mechanic actually works as a "bounce off the ground."
In fact, it's more like a physical push off the surface, rather than a second jump in the air. The name "double jump" turned out to be misleading. Even players with 70 hours in the game admit that they had been performing the move incorrectly all this time, which hindered their exploration of the world.