Thanks all.
I will put a new battery in one of them to try but the roller shutters were already fitted when we moved in two years ago. I have since bought an extra remote for the garage door. The window one hardly ever gets used. The spare for the door never gets used. All 3 of them work inside the garage.
I have opened the control box today to see if anything was obvious in there. I have a wiring diagram of said box. There are no batteries in it.
I am going to contact the manufacturer tomorrow. Either that or the local company that fitted the shutter and door.