I need some fuel sending unit experts please

The voltage test on the IVR at the fuel sender connector was done with a power pro ( alternated positive negative) and separately by digital multimeter. This produced a broad range of voltages at various intervals but nothing that looked like consistent intervals.
I do not understand how you used the power probe.
Please explain.,

I don't know what digital meter could possibly show as it struggles to display the rapidly changing voltage unless it has a scope function.
It's not really a square wave.
Did you watch the video?