Boot lock stopped working

[Arapo]

2 and a bit months into ownership, and I am convinced these cars have a mind of their own...

The boot will not lock any more when I lock the car.
Tried with the door lock button on the inside as well, but nothing. Also the alarm will not go off when I open the boot while the car is locked. It did go off the first time, then it stopped..

Any ideas? Has anyone had it?