How long have you had the Denon? And as above can you you check the settings on Denon. I'm back now and on BBC1 HD its ouputting PLii Cinema. On one box its openvix 2, a Vu+ Duo2 and on the other its openvix 6.3 on an axhd61.
When you change the audio settings on the mutant are you pressing green and for PCM does it say NO. ? I'll do a few screenshots of your AVR settings in a while. NB When you go to BBC1 use this one 10847 V, 23000, 3/4, DVBS2-8QPSK and better still re scan it with signal finder.
This is what I get on denon display. This is using optical cable, for axhd61 and the second one is using hdmi for duo2 shown as xtrend for now but same info. The info button will only tell you what you have set.