Nexus Charging Orb have a slipping problem?

Recently purchase a Nexus wireless charging orb to charge your Nexus 4?

Well my Nexus 4 seems to slip off no mater how I position it. Not sure if it is a defect or bad design. I cleaned both surfaces and tried multiple time. Every single time the Nexus 4 will slip down, touch the table, and eventually prop itself off the orb causing the phone to stop charging. Very frustrating since this Orb cost $70.

Here is a timelapse of my case-less Nexus 4 slipping after about 5 minutes. Dont mind the speaker in the shot. It is not on.

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