Thanks for the update, but the problem remains, on film capacitors when measured at 600mV, it shows negative ESR, when measuring the same capacitor at 300mV, the result is correct.
I have a 1833 device, and not the one on your video, and it shows a negative ESR when measured with a 600mV signal, when measured with a 300mV signal, the readings are positive. The capacitor and frequency are the same.