check you logger settings, and comment powercalc:
# custom_components.powercalc: debug
or, if you have Powercalc all set up in the UI, check you havent enabled debug mode there (although I am not sure that would survive a restart, so probably not)
it might be worth a chat with Bram (author Powercalc) why the discoveries happen so very frequently. I guess it would even be an option adding a flag there, so it doesnt keep trying on that particular device. But that you’d have to talk to Bram about in Powercalc - Virtual power sensors, or his repo