When jumping or falling in versions prior to 1.14, the camera would do a sort of "bounce" to simulate the player leaping up and then falling down as well as moving the held item down and then back up again. This also applied to falling as a whole, and the camera would slowly move forward and stop at a certain angle. In the release version of 1.14 and all updates following it, this feature doesn't seem to be present anymore.

This is likely to be related to MC-159952, as it also only appears in versions after 1.14 and 1.14 itself, and is also an issue pertaining to the player's camera.