Central unlock via key

Hi I have an issue with my 2004 camper , everything works except the central door unlock using the key in the door , it used to work but just decided to  stop functioning , I can use the  remote fob to unlock,  and the drivers door switch works to lock and unlock all doors when in the van ,  but not when I physically use the key in the driver or passenger door to unlock or lock all doors , I’ve checked the switch wires in the door lock and I can see them operating using a multimeter , and if I hold in either lock or unlock the window open/close works so thinking electrically everything is good in the door  and it’s a module /ecu. Issue ?  Or is there a way I’ve accidentally disabled the function. Anyone have any ideas or experienced Anything like this ?  Any advice would be appreciated before I approach Toyota 

Edited March 21, 20214 yr by Alexmee
Added detail