Double Socket Switch Resistance When turning off

Have a double socket in one of the spare rooms literally turned it on to print a label and then when turning it off there was resistance halfway was able to turn it off and tried turning it on and off again and no resistance this time not sure if it's a blip or should get a ellecy out to switch it over. I dry clothes in that room due to the poor weather at the moment, there is a dehumidifier plugged into the other side. No funny smells and it's not hot. This socket is only ever used with the dehumidifier or the label printer.