Works on Canon 5DII but paralyzes the USB connector on the camera ?!

First of the good ahead of what actually 5 stars would have earned:
- Provides power :)
- Is recognized by the 5DII than 100% full battery
- Long cable that runs smoothly through the cable channel on the battery compartment
Connecting cable with plug connection, which means you could replace the DC coupler itself eg by a 12V connection and needs only a battery adapter -

Now the probable 90% unimportant, but essential for me gripe: I had originally bought the adapter in order to support my 5DII for timelapse recordings with electricity. The camera via USB cable to an Android Tab (Galaxy 3 8.0) is connected, where the app DSLRDashboard takes control. Unfortunately, this connection no longer works when I use the DC Coupler! The USB connection is continuously interrupted and rebuilt. With normal battery everything is ok.
I can not test how it looks with different tabs. But I do not see why it should be because, since it works with batteries.

Since this is an equally unexpected as well as seemingly inexplicable problem, I have to deduct star.

If someone has had a similar experience, I would appreciate feedback.