Ignis AWF595 Washer/Dryer goes into tumble dry when not set.

I have had a call to a Ignis AWF595 Washer/Dryer which I believe is a Whirlpool machine.
When set to wash with the dryer control knob set to ‘0’ the machine still tumble dries, this is intermittent.

I have tested this at the end of the spin cycle and the machine shuts down as it should. It goes onto dry when set to do so.

I have checked for earth faults, checked the pressure chamber and the dryer control knob to ensure it’s not turning on the selector shaft.

Any suggestions would be appreciated.