odd behavior at water heater elements

[CheckItOut]

Doing my usual check of the water heater elements and noted the settings on both thermostats to be 150 (water temp at kit sink was only 90.) I cut the top thermostat off (90) and checked the voltage at the bottom and got 75. Then checked the top one and got normal voltage with it in the off position - always on. Let the unit sit for a while then came back and same deal. I never heard the normal clicking on and off when adjusting the thermostats. Sound like a thermostat issue? Will be written up to repair but I am curious.