Central locking

[Blurtar]

I have a fault on the central locking that I’d like to sort. I now have a working siren after replacing it due to the battery leak issue so that’s sorted, however, the one remaining niggle is that the central locking doesn’t unlock when the key is removed from the ignition. Everything else works fine including auto lock.

If I forget to press the door switch to unlock the doors the system will not lock from the remote. If I remember to press it then it locks fine.

So basically the fault is the auto unlock from ignition off.

Any ideas please?

Thanks.