The speed boost given by the "Soul Speed" enchantment also works on spectator mode.

How to reproduce:

1. Place soul sand blocks.

2. Put on some boots with soul speed.

3. Enter spectator mode.

4. Fly over the soul sand, the camera and the speed boost you get prove it.

What should happen:

The spectating player should not suffer this effect.

What is happening currently:
The player in spectator mode will drop particles (MCPE-165655) and gain the speed boost from the enchantment (This report).