Some projectiles continually accelerate after pushed by slime block + piston (= negative friction?)

Steps to reproduce:

1. Flat world, no mob spawning, no griefing.

2. /fill 0 -60 50 0 -58 50 smooth_stone

3. Make an impulse, needs redstone command block with /summon minecraft:fireball 0 -59 0.0 or /summon minecraft:wind_charge 0 -59 0.0

4. Place a sticky piston at 0 -58 -3 facing south, and place a slime block on its face.

5. Make a repeat, needs redstone command block under the sticky piston with /execute at @e[type = minecraft:fireball] run tp @p ~-7 ~-1 ~ facing ~10 ~ ~ (or use wind_charge instead of fireball)

6. Place a lever on the repeat command block and a button on the impulse command block.

7. Press F3.

8. Press the button.

9. Start screen recording.

10. Flip the lever.

11. After the projectile hits the wall, examine the recording frame-by-frame and note the player’s Z coordinate.

Expected result

As the player moves along with the projectile, after the initial push the Z coordinate increments by the same amount on each tick. I.e. the projectile moves at constant velocity.

Observed result

As the player moves along with the projectile, after the initial push the Z coordinate increments more and more with each tick. I.e. the projectile perpetually accelerates.

Note: I am not sure if this is a bug in certain projectiles, or in the sticky piston + slime block interaction with entities. Armor stands and snowballs do decelerate after the initial momentum give by a sticky piston + slime block, but I am not sure if they slow down by the correct amount. Those are the only entities I tested.