Im having some problem with the boot lock on my 3 door

When you open the car using the key from the drivers door the boot lock fails to open was the first problem so you would have to go round and open it with the key and then it would stay unlocked.

After a few weeks i tried it again and when you go to unlock it with the key, the lock doesnt actually stay unlocked. You have to put the key in, turn it round and push the button in with the key still turned round. If you try either way the lock wont stay unlocked.

My question is, what is the likely problem? Do i just need the lock itself rebuilt?

Or is it two seperate problems? One with the lock and one with the centeral locking solenoid? When opening the car from the doors you can hear the solenoid in the boot moving so its def still working

Thanks