El Capitan GarageBand USB Mic problems

Just installed El Capitan on my 2015 Macbook Pro over the weekend and now every recording I make ends up stuttering.

This wasn't an issue before. I have a USB mic going into Garage Band and while it may start out recording normally,

after a few seconds it suddenly begins stuttering repeating a small fragment of the recording.

This is on the recorded track, not just playback (you'll see the same small waveform repeated over and over)

Any ideas what is causing this issue?

Did a restart and started a new project, unplugged and replugged in mic.

Wasn't an issue until two days ago.

Is anyone else having this issue?

Mic is a Shure PG42USB.