Remove the oven from the cabinet, remove the rear cover and check the sensor wire harness from the sensor plug to the control board.
Eliminate the sensor plug and connect wires using the high temperature porcelain wire nuts (part number AP3440522
Check the sensor plug at the control board for the possible loose connection.
If all of above did not help then the control board has to be replaced.
In order to provide the right part number for the control board I need the complete model number of the unit.