Why do my puntos headlights lights keep turning on when the car is not in use?

What is your question?

I purchased my 57 plate fiat Punto grande about a month ago and I had no issues with it. However, over the last few days the main beams have started turning themselves on even though the ignition is off and the car is locked- the only link we can find is that they only come on if the heaters have be left "on" (but they're not on because the engine is off) so we're having to disconnect the battery so that it doesn't die. Do you have any idea what could be causing my lights to turn themselves on when the car isn't in use?

What makes this problem better or worse?

When the heaters have been on

How long has your 2017 Fiat 124 Spider had this problem?

A few day