NFS issues

[Bedlore]

Okay, so an update. I installed a new image now and started fresh. I added the 3 audio links as NFS this time. When trying to index them I get the following:
$ tail -f /var/log/mpd/log
Jun 26 22:27 : exception: Failed to open /var/lib/mpd/music/NAS/Lossless: Permission denied
Jun 26 22:30 : exception: Failed to open /var/lib/mpd/music/NAS/Vetting: Permission denied
Jun 26 22:31 : exception: Failed to open /var/lib/mpd/music/NAS/Pre-Staging: Permission denied

pi@moode:~ $ ls -l /var/lib/mpd/music/
total 12
lrwxrwxrwx 1 root root 8 May 10 09:00 NAS -> /mnt/NAS

pi@moode:~ $ ls -l /var/lib/mpd/music/NAS/
total 472
drwxrwx---+ 2765 pi www-data 114688 Jun 14 22:34 Lossless
drwxrwx---+ 3 pi pi 4096 Jun 25 22:35 Pre-Staging
drwxrwx---+ 3883 pi pi 344064 Jun 21 14:10 Vetting

pi@moode:~ $ ls -l /var/lib/mpd/music/NAS/Lossless/Younee/My\ Piano/1-01\ Ausflug.flac
-rwxrwx---+ 1 pi www-data 26628460 Dec 25 2017 /var/lib/mpd/music/NAS/Lossless/Younee/My Piano/1-01 Ausflug.flac

If I try as www-data it fails,
pi@moode:~ $ sudo -uwww-data ls -l /var/lib/mpd/music/NAS/Vetting/

Any thoughts?