Shuffle on album level

[PJVervoorn]

I can’t get it to work with (single or double) quotes.
The path to my music is USB/6364-3239/
Music bought from Bandcamp is in USB/6364-3239/_Bandcamp/
It doesn’t work with any of these:

Code:

filename “USB/6364-3239/_Bandcamp/“
filename “_Bandcamp”
filename ‘_Bandcamp’
filename USB/6364-3239/_Bandcamp

It only works when I use 

Code:

filename _Bandcamp