CFD of Drone Downwash does not look Right

Hello All!

I am working on a custom drone shroud and was hoping to get some help with the simulation as it is not looking correct to me and I have tried a lot.

The air velocity seems to spread out immediately and unnaturally away from the rotors instead of going straight down. I have tried this with both a fan model (200 and 300Pa pressure change) and an average velocity (20m/s) model.

I am really at a loss here, if anyone has any hypotheses or can tell me if I have set up my simulation incorrectly, I would really appreciate it.

I cannot seem to make my projects public (it is an academic account) so unfortunately I cannot share the project links, but I will share as much information as I can below and I am happy to provide more if need be.

What I Expect: (from the internet)

What I get: (Showing air speed velocity magnitude)