Key not recognised

[DarrenReis]

Hi there , I have a 2015 phev in the uk . Which has now decided that it doesn’t recognise the key fob , car works absolutely fine apart from an extremely annoying dinging when you open the doors . Put new battery in fob , same thing ! Went to Mitsubishi got another new battery same thing ! . Got another new battery from timpson, same thing !

The chap at Mitsubishi says it should automatically just work buts it not and when I am heading out in the morning and late evening this dinging is driving me and my neighbours potty

Any suggestions gratefully received