Some AAC audio streams practically unplayable
This is a strange one. A couple of services that use AAC audio don't work properly while others (also with AAC audio) work just fine. The issue manifests as very low audio levels in VLC, coupled with only the higher frequencies hearable (aka. no bass). In Kodi the channels don't have any audio at all and Kodi struggles to keep the video playing, presumably because it attempts to sync with the broken audio.
I am not sure if the issue is in ffmpeg or tvheadend. See the URLs below for the --tsdebug files from one of the affected services: