Odroid C2, CoreELEC 8.95.7.
When I have Audio output setuped to the 2.0, AAC multichannel (tested 2.1, 7.1) doesnt work as multichannel on passthrough. AVR shows and play it like stereo. DTS/DD etc. works fine, when passthrough, which is expected behauviour (output settings shouldnt matter when passthrough).
When I setuped Audio output to the 5.1, AAC multichannel works in both passthrough/decode (and AVR shows PCM).
For the record, AVR is Pioneer VSX-930 and it knows AAC by specifications.