I'm having issues setting up the LM13700 as a floating resistor and measuring the correct resistance values
Using a DVM might not do the trick here, especially if it is auto-ranging. I would suggest applying a voltage while measuring the current and then calculating the virtual resistance from there. The problem is that the meter will likely always apply the same injection voltage in all ranges and it will always start in the highest range. If the voltage produces a current that is within the current range, it won't change to the next range and you will always read in the highest range.