After doing some research, I would have to guess that exact same thing.
How old is your crockpot? Many and most have the low/high or low/med/high setting now, and low is usually 200 degrees, where high is 300 degrees.
Maybe you can test it by maybe cooking something real easy so you can keep an eye on it, or just put water in it

and test the water temp.
Whadya think?