voltage measurement problem

My DSO show voltage values about 1/4 or less of their real value, AC or DC. For example an AC 12v appear 4v on the DSO and a DC 16v appear 1,3v.

Someone known a soft issue or is it an hardware problem? I replace the probe but no change…


It’s strange, would you please verify the settings? And which voltage value you are reading from? Thanks!