17 beta 6 piano noise?

I'm getting a strange single key virtual piano noise upon start-up and play - is this intentional or has DVR unwittingly picked up a VST instrument from elsewhere?

I have disabled all VST plugins - still there. Upon startup I get a high note then a low note and upon playback a high note starting and slightly lower high note stopping. This was not present with 17b5.

Assuming Windows and "Use MIDI Audio Console" is enabled? Is the MCU option selected or HUI?

Thanks for your reply. Yes I am using an Avid Artist Mix with MCU.

Sorted! I had to reapply resolve.exe app in the Eucon control panel settings. It was using MS wavesynth and had lost the Eucon midi. Thanks Reynaud for your pointer.