I posted a question on this topic in the Whirlpool Forum here in Australia and was advised to try again here on CoreELEC discourse.
In summary, I am getting occasional audio dropouts when playing music using the PartyMode Autostart addon. I have the N2 running latest release CoreElec connected to an Onkyo AV receiver with HDMI. When I’m listening to music with this config, I have the TV off (well, standby actually). Note that a HDMI lead from the AVR to the TV is still connected, but the TV is off. I do not get any audio dropouts if I have the TV on, either when playing just music or video (streamed or stored on NAS).
I have tried many different audio and video settings in CoreElec, different HDMI cables and different ports on the AVR.
I suspect an HDMI handshaking problem, since the signal indicator display on my AVR goes blank when a dropout occurs.
Here is a link to my original query on Whirlpool which contains a more detailed description https://whrl.pl/RgaJrM . I would be extremely grateful for any help in solving this problem.