Central locking mystery

[Nicola 50]

I have a RAV4 on a ‘54 plate. I sat waiting in the car and locked it using the central locking button in the door inside the car with the key in the ignition. Unlocked it the same way to let passengers back in the car. Drove home. Tried to lock the car as usual using the key fob and nothing happened. Tried to lock the car with the key in the door, tried drivers and passengers, nothing happened. Car will still lock from the door button controlling central locking inside the car. 
Any ideas what’s happened to the key and fob operated central locking please? 

[painterman 55]

Strange one this had it at work do you have 2 keys for car if so keep the one thats not working away from car and start it with the other one it may reset the locking system may not be this but has worked in past check Battery in fob too in both keys if you have