The documentation from 1.14 shows the following information for the "minecraft:jump.static" component:

It tells the user that the default value for the "jump_power" member is 0.42. However, if I give the jump_power member a value of 0.42 instead of not including it (which is meant to set it to the default value), it will make the entity extremely slow (for some strange reason). However, if I don't include the "jump_power" member, the entity will move fine.