Hi,
I tested it with my DMM6500 but I simplified the schematic a little (yes that's possible)
I just connected a current source to the DMM6500 and shorted the voltage terminals with 50 Ohm.
So I should get 0 Volt all the time:
I got this: no sound, sorry, when the voltage changes to -2.47V instead of -36mV, it is still -36mV on the terminals.
edit: one more thing I didn't have a relays sound on 100V range (the same like lower ranges)
edit2:
When no resistor is connected then for 1.00A I get -21mV for voltage (and much more in the 100v range and up)
When I short the voltage terminals I get -38mV (and again much more for 100V range and up)