Define what you mean by "normally". If the drum doesn't stop, how is that normal?
The drum control is separate from the heat control. If the drum doesn't stop, the part that runs it, probably a relay, is sticking.
That could be because the signal to the relay is malfunctioning or the relay itself is bad.
If turning on the breaker again does not restart the drum, then it is more likely the relay control is malfunctioning.
Power is removed from the relay by the control or the breaker. So, if it restarts after turning off/on the breaker, the relay is stuck.
If not, it is the control.