Would you be willing to test a few episodes of Season 33 of this show (output to MP4/AAC),
and tell me if your end result video file has audio muxed in?
TANGd878
I have not forgotten ..
.. but the DL (with VPN) takes longer than the episode length
(video <1 MB/s, audio <100 kB/s)
SF show dl audio and in "Downloaded" it shows AAC ..

-= click pic to enlarge =-
.. but my result have also no audio - and no errors in log, only:
[code][Info]: Roku Download, skip this unavailable audio file[/code]

Due to a lack of free time, I won't be able to do any more tests until tomorrow