I am a newbie and would be grateful for some advice on some strange intermittent locking problems on our Ford Focus. There are many variations?

Variation 1: Try to lock using remote and it locks then immediately unlocks, only way then to lock the car is to put the key in the passenger door and manually lock, also sometimes just waiting 5 minutes and trying again with the remote works OK.

Variation 2: Car seems to lock with Remote OK but when you check the passenger door is unlocked.

Variation 3: Car seems to lock/unlock OK, but around 5 mins into a drive your hear the sound of one of the doors unlocking, sounds like one of the back doors but not sure.

Variation 4: Car seems to lock/unlock OK but as you are driving around have varied and random instances of door locks locking and unlocking!

Thank you