Lower FAIL displayed in withstanding voltage test

QI am getting a "Lower FAIL" reading even though I tested the withstanding voltage of a known-good product.

A

"Lower FAIL" is displayed when the current value is lower than the lower limit.
Usually, only the upper limit is necessary to detect leakage current
Please change the lower limit value setting or turn the setting OFF.

NOTE:
If all "Upper", "Lower", and "FAIL" lights, the test voltage is exceeding the set value.  (Voltage comparator function)