Here are some steps you can take to address the temperature issue.
- Make sure the black rubber piece is in place that insulates the heater block.
- The layer cooling fan can sometimes overpower the heater. Try reducing your maximum fan speed in Settings > Filament > Cooling.
- Run PID Tuning.
- Look through the gcode terminal during a print and see if there are any errors being reported (specifically MIN TEMP errors). This would indicate a break in the thermistor circuit.