I'm glad that you got the SDRduo working, The most obvious
thing from your pictures is that the tuning is not centered on
the VDL2 signals. Make sure to set AFC on in the VDL screen.
Also, I have found that VDL2 decoding is very sensitive to levels.
You may have to play with the receive levels in the transceiver
screen. Too much signal will stop the decoding. "Auto" is not
always best for the gain. This is also true for ACARS decoding.
Hope this helps,