Bonavita kettle heats even when turned off.

hi all. i've got a bonavita variable temperature kettle. it's about 10 years old. recently it's started doing something really weird. as long as it's plugged in, the base supplies heat to the kettle, even when the base is turned off. if i do turn it on, it supplies heat, regardless of the specified temperature. so if i set it to 93 degrees, it'll just furiously boil it way past that. as best as i can tell, the base is telling the kettle to heat up as much as possible, regardless of what i do, as long as it's plugged in.

has anyone experienced anything like this before? does anyone have any recommendations on troubleshooting or repair? do you think the problem is with the base or with the kettle? i saw this video in which the guy has a similar but distinct problem and it's with the kettle. he doesn't seem to have the issue where it happens even when it's turned off though, which makes me think it might be a different problem.

any advice would be appreciated! thanks!