Dahua Speeddome Incompatible With Dahua NVR

So I bought this Dahua Speeddome because it seemed like a good deal.

I knew it wasn't POE compatible when I bought it, but it said it came with an external PS, so I figured ok. It says it works with 802.3.at, Poe +.

But, when I try to use it with my Dahua NVR with built in POE 802.3.af switch, it starts clicking and shaking etc, because it is drawing some but not enough power from the switch. It works fine if I use it with a non POE switch and its external PS, but I think it's stupid I can't use it with its own NVR.

Do you think this is a defect, or should I use both the external PS and let it draw whatever it wants off the switch?

To recap: you knew it wasn't compatible when you bought it, but now you want to know if it is a defect?

If you use the external supply, it shouldn't draw any power from the switch.

Yes, meaning I knew it could not be powered by a regular POE af switch. Which was ok with me, as I figured I would just use it with the external. I assumed it would not draw any power at all from the switch, since it is not an 802.3.af device.

If you use the external supply, it shouldn't draw any power from the switch

When you say "should" do you mean that as soon as I plug-in the wall-wart it will stop drawing power from the switch? What makes you think that?

Can you turn off the POE power of the port on the NVR and just use the POE injector?

I don't see how to turn off POE on this Dahua NVR, it's not like a managed switch. I'm going to look again.

It didn't come with a Poe injector, just a 24AC transformer with leads that go to tails on the camera.

I can use a POE splitter to split the POE from the NVR, but that seems dumb. It's says it draws 13 watts without IR on, so it's just over af capability.