Can DM500HD receive Dolby sound channels

[jsryork]

I have a DM500HD connected to a Sony DN1050 amp. I watch FTA French TV on Eutelsat 5.0W [on 11591 V 20000 QPSK]. Up till April all was OK. Since then I get both Video and Audio on France 3, but Video only for France 2 and France 4. In the About menu, Service, PIDs, the Sound PID shows N/A for Fr2 and Fr4, and 0x00e6 for Fr3.
I have found this note:
<<

• 
  Eutelsat 5 West A (5°W), 2016-04-05
• France 2 HD has left 12648.00MHz, pol.V (DVB-S2 SID:1282 PID:220[MPEG-4]France 2 HD (France) broadcasts in DVB-S Clear on 11591.00MHz, pol.V SR:20000 FEC:2/3 SID:257 PID:120[MPEG-4]Bis & Fransat & Orange: France 2 HD has left 11096.00MHz, pol.V (DVB-S2 SID:426 PID:2461[MPEG-4]
  
  /2462
  
  French,2463
  
  qaa,2464
  
  Audio Description)

>>
and this thread:
Just Sharing This - fransat fta channels from 5 april
which says the problem is with Dolby encoded sound (which ties in with the Fr2/Fr3/Fr4 effect), and mentions AC3 downmix (OFF) and HDMI cables.
But my problem seems to be that I get no Sound PID, right back in the Tuner, rather than in the subsequent audio format decoding.
Do I need a more modern DB ?
Thanks
John