Symptom :One of the three LEDs appears to glow when all doors are closed and the car is locked.   Cause : when you tried one of those stupid replacement LED w5w bulbs in the boot door you created a momentary short and damaged the integral diode of the lamp holder.   Cure: Remove the lamp holder(s) and disconnect from the car by pinching both sides of the plug and pulling. Remove the bulb. Either, with a multimeter on diode test confirm the diode reads in both directions and replace