I have a pit boss Austin XL. Roughly 2 years old. I recently noticed while using that something is going on with it not cooking at setpoint on controller. I have cleaned firebox out and cleaned temp sensor on left hand wall. I set it to smoke yesterday and both digital read out and manual readout on lid went to 500 and went into her code and shut down. It doesn’t matter what setting I set the dial to it just keeps peaking out. Any help would be appreciated!