You would think so. I think the issue is they don't bother to calibrate, so they're all over the place. These pictures were taken at the same time, showing the displays on the two heaters and on the temperature probe in the water. The moral of the story is don't trust the temperatures that cheap electronics report, and if possible, do an offset calibration of your own so that you can set the thermostats accordingly.
I have a power cut off probe on these for runaway heating events, and the remote probe has been calibrated independently to within 1 degree F. I can't complain about the Hyggers when I have yet to receive an inexpensive heater with an accurate thermostat, and some of them in the past have been 10 degrees off. It does make me wonder if I should check to see if there's a calibration function available on either of these, though.