`unit_of_measurement` Does Not Change

When I set up an MQTT based sensor I didn’t get the unit of measurement right, I just put C instead of °C and left it like that for quite some time.

I’ve updated it in me config now but the widgets on the UI (Lovelace & legacy) still just show the value with no unit next to it & no graph is just produced when you click it, just a funky line drawn with a different colour for each value :slight_smile:

I’ve tried using recorder.purge as suggested in other posts but I still have the same issue. Do I need to purge the WHOLE database to correct the value? Is there a way just to purge this single sensor, I’d rather not lose my whole history if I can avoid it.

How do I remove the sensor totally then I can add it again?