Player Movement Doesn't Work Properly

When attempting to change a players movement speed via behavior events where a component group is added with a new movement value, the movement will take effect for about a tick and then revert back to default, even when the movement component has been removed from the general components section. This requires us to use an environment sensor (or some other method) to update movement every tick, which will cause unnecessary lag, especially with multiple players.

This is probably happening with underwater movement as well.
Perhaps a potential fix could be adding the attributes system that Java Edition has?

Steps To Reproduce:

1. Download, install and start a new world with the supplied pack (experimental features on)

2. Run the following command

   /event entity @s player_movement

   /event entity @s player_movement

1. Observe that your movement speed will speed up for a tick

2. Run the following command

   /tag @s add player_movement

   /tag @s add player_movement

1. Your movement speed will now be properly doubled

   1. The tag is a trigger for an environment sensor trigger that will constantly trigger the player_movement event (with multiple players this can get quite laggy)

Expected Results:

• Player movement saves across component groups without the need to constantly update it

Actual Results:

• Player movement reverts to the original movement when not constantly updated