Pi3 Volumio2, Arcam rPAC USB DAC & stuttering FLAC's

I have a Pi2 with HiFiBerry DAC working perfectly with Volumio 2 (2.55) connected to a wired home network and accessing music from another Pi (3 this time) which is running Stretch and AssetUpNp server and a USB HDD for storage (accessed via Samba for file management).

I have added another Pi3 with a USB DAC (Arcam rPac) but unfortunately whether in 2.0 or 1.0 mode any FLAC that is 24 bit HR stutters and are ultimately unplayable.

Output device is set to “Arcam USB Audio 2.0”, I2S off, DSD direct on, 2mb buffer, 10% before play and Mixer Type set to None.

aplay results in:
**** List of PLAYBACK Hardware Devices ****
card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
Subdevices: 7/7
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
Subdevice #4: subdevice #4
Subdevice #5: subdevice #5
Subdevice #6: subdevice #6
card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 IEC958/HDMI [bcm2835 IEC958/HDMI]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 5: A20 [ARCAM USB Audio 2.0], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0

Are there any tips towards getting HR files playable with this new Pi/Volumio setup

All resolved - turned out to be a faulty switch port, solved by rebooting or swapping port.

Someone did post information elsewhere in the forum about changing the mode on the Arcam rPAC which was useful too.