All, please note that where 5V is referenced in the “strange readings” it is actually 5mV and the high allowed reading is 6.42mV. This would not be out of range accuracy as this is probably the bottom of the 100mV range. If the range accuracy is 1.5% (1.5mV) then this is the tolerance. The actual reading is better than that. The actual reading tolerance is described in a more complicated but more precise fashion.
See the manual for the exact description of the accuracy and the calculations that derive it.
The 4284A/4285A/4286A family of LCR meters is my favorite of all of the HP, Agilent, Keysight LCR meters. They always read more accurate than the spec. and were extremely repeatable.
Don Bitters
