Whenever 192kbps track exists for a particular language,
128kbps isn't listed and therefore CANNOT be downloaded at all.
ms-dfav
How to get AAC 2.0 128 when only AAC 5.1 192 is offered in SF ?Analyze the serie/movie and select you're codec/resolution/subs
and offered Audio AAC 5.1 192, now "Add to Queue" and close SF
Go to %AppData%\DVDFab\StreamFab\taskdata
and open the file Netflix in Notepad and find "audioMap":["ey
You will see a token that starts with:
eyJiaXRyYXRlIjox
OTIwMDAsImNoYW5uZWwiOj
Ychange this part to:
eyJiaXRyYXRlIjox
MjgwMDAsImNoYW5uZWwiOj
I(of course you can use search/replace)

background:
OTI is 192 - Mjg is 128
OjY is 6ch - OjI is 2ch
save the file, open SF and start the queue => that's it