minecraft:underwater_movement component does not work on players

Partner Rank:
3

Partner Team Reporting:
Entity Builds

Verification builds:
1.16.20.53 - 4386174

1.16.100.50 - 4459742

Summary:
Modifying the value of the minecraft:underwater_movement component has no effect on the player's speed underwater

Impact:
This bug prevents creators from changing the swimming speed of the player which in turn prevents the creation of aquatic content with various mechanics

Repro Steps:

1. Create a behavior pack which modifies the player behavior
2. Change the value of the minecraft:underwater_movement component
3. Apply the pack to a world and enter the world

Observed Results:
The player's swimming speed remains the same

Expected Results:
The player's swimming speed should change correctly based on the value specified in the underwater movement component

Screenshots/Videos attached:
No

Regression Builds:
This has always been an issue

Notes:
I've attached a behavior pack that helps reproduce the issue