Handbrake bakes firmly MX5 NC

Hello, in my MX5 Bj 09 I have a problem with the handbrake. If you park the car overnight with the handbrake tightened, you won’t get away from the spot the next day. The brake pads seem to be stuck or rusted. Only after a bit of hearty gas the car rolls with a loud jerk. After that you hear a few hundred meters still a grinding of the discs and is good. Especially in the winter, when the brakes get wet. Weil 6000km first on it and the problem existed from the beginning. Does anyone have any idea what that should be? Do I have to do something? Warranty? Greetings Stephan