Any Ideas?

When I remotely unlock the doors they open but lock again immediately doors unlock fine when using the key.

 

probably an issue with the alarm unit as most have a security feature that will re lock the doors if it is unlocked with the remote but no doors or boot are opened within the time limit (usually 30seconds or so). I think this feature is for accidental unlocking ie when putting keys in pocket and walking away etc.

You may find there is an alarm option to turn it off and see if that sorts it or you could try a system reset (or disconnect the car battery and discharge the system)