Doors lock but wont unlock..???

Hi all, we have a 2013 Freelander 2 td4 HSE, about 45,000 on the clock. Its been parked up for a while due to the bug, and the battery warning has come up a few times. Wife reported the doors all locked OK when she went into work, but wouldn't unlock via the keyfob. She could open the windows via the fob and reach inside, the doors unlocked from the handle, and via the buttons on the dash. We can hear the solenoids working, and the alarm chrips.
I took it for a nice run on the M3 today and the battery is fully charged, but again I can lock it with the fob, but it wont unlock. The rear hatch DOES unlock from the keyfob.
Further diagnosis, I see the black lock knobs on the door handles move freely on the passenger doors when I blip the fob, but the drivers side knob feels crunchy, and is reluctant to move. It also seems to lock / unlock all the others, there must be a master switch in there, so if the drivers door wont function, neither do the others. Good design there Mr Landy.
I'm guessing its old age, I gave it a squirt of dry silicone lube, I see on the interweb many folk report similar problems, suggestions to swap the battery, but this feels mechanical to me. I guess the next step is to rip off the driver side trim and have a poke. Any thoughts?

Welcome to LandyZone.

This is the Introduce Yourself section for Introducing Yourself.
We have several sub-forums which are vehicle specific so asking questions in the relevant area will allow it to be seen by more forum members who may be able to help. In your case, over 'ere.

https://www.landyzone.co.uk/forum/land-rover-freelander.9/

Oops. Feel free to delete this one, I've posted in the right place.

Hello and welcome

Welcome to the forum