can a crock pot go bad?
Depending on the design, the heating coil may have collapsed and is shorting out at various points

This may cause it to run hotter than intended, and result in problems you describe

Measure the current with a meter and compare to manufacturers label, if much higher it's time to scrap it. Unlikely to be easily repairable if it has a heating coil

If it is running hot it is likely to fail soon and not heat at all

Modern crock-pots used solid elements, not coils. They also often have physical temperature regulation systems, not just a simple element selector switch