Audio dropping out on right hand side usb port of 2015 macbook pro retina

Why am I experiencing audio drop outs on the right hand side USB port of my Macbook Pro Retina 2015?

Audio starts to crackle and sounds like the bit rate has been reduced dramatically.

External Sound card is a Sound Devices USB Pre II.

Only work around at this stage is to plug sound card in to the left side usb port.

This is unacceptable Apple.

MacBook Pro with Retina display, OS X Yosemite (10.10.5), Soundcard - Sound Devices USB Pre 2