Scrapps79

Hello All, Can anyone help. I recently changed the battery in my smart key fob and since doing this I'm finding it difficult to lock the car. The fob itself and the exterior door button don't seem to want to lock it. If I stand there long enough, with enough patience, it will finally lock. The car unlocks and starts with no problem. Is this a case of getting the fob reprogrammed Is this something I could sort myself? Many thanks