Keyless door unlocking issues on Discovery 4

Hi I've just got my 2009 Discovery 4 and found that my driver door doesn't unlock when I try to open it with the keyless entry. All of the other doors open fine with the keyless entry. I can unlock/lock the driver door with the unlock button on the fob.

Interestingly, if I use the fob to unlock all the doors then they all open fine except the rear left which needs to be opened from inside the car. But opening this same door with the keyless entry there is no problem and that will then unlock all the other doors, including the driver door.

I'll be getting the dealer to fix it but just wondered if there's a way to reset the key fob or anything else I can check? Seems like a weird problem.

EDIT: Not sure if related, but I changed the battery in my second key fob prior to noticing this issue as it wasn't working. I didn't check the keyless entry prior to changing this battery so not sure if this caused the issue or not.

It might need a couple of door actuators, but a diagnostic read will confirm that.
I'd get the keyless entry disabled too, as it's very easy for car thieves to steal with keyless.
Get it set to work on remote only, which is much more secure.