Underwater Movement bug

Performing a frame perfect Digital R button press the same frame as pressing B to jump forward, while holding up on the stick and down on the L button should produce a normal jump, but instead it provides you with a lot of extra forward momentum.

Expected result:
https://youtu.be/p0y7qb07VfY

Actual result:
https://youtu.be/6kR60_UeRQ4