DMM6500 display becomes non-functional during certain USB controlled operations

We use a PC USB connection to control a DMM6500 which measures and records periodic current/voltage levels in a test fixture. It works great most of the time. Occasionally however, updates or other issues crop up and we need to troubleshoot and fix the problem. This would be much easier if we could see the live values on the meter's front display while running the tests. However, ever since we first started using the DMM6500, the front display freezes during certain periods, probably when the PC is exercising its control using the USB connection. I've found nothing in the manual that references this behavior.
Two questions:
Is this normal?
Is there a setting or method to avoid it?

As I said, it's not a major issue - just more of an inconvenience.