Latest VCDS and Hex-Net problem

So trying to view my injector measurements on '13 Q5 2.0T and no matter what I choose, I cannot run output tests.
System is using UDS mode so Measurement Blocks is greyed out. Going into output tests to see which injector may be bad, I get "Refused by Control Module" 7F 2F 81
Not sure if its a problem with my vehicle, but all the videos I've seen shows a CAN protocol, but my car seems to default to UDS...
Thanks! and feel free to delete if not in the right area

The protocol a control module uses is what it is; it's not selectable by VCDS.

Engines can be very fidgety with output tests. Start the engine, let it run for a minute, shut it down, turn on the ignition (but do not start the engine!) and then try output tests again.

-Uwe-