New M1 Max, Monterey, XDJ-XZ: RB major stuttering

RB 6.6.3, Driver 4.0.0, just updated the firmware on the XDJ-XJ and I'm getting a ton of stuttering in linked mode. Every few seconds it pauses for about half a second. Now it's been running for ten minutes maybe and I'm getting it every 30 seconds or so - seems to come and go. Definitely not going away though.