Bad earth?

hi all im picking up my 03 td5 next week however it has one issue which im hoping isnt a big headache! When you go to unlock the doors they wont stay unlocked using the fob. To get the fob to work youbhave to make sure they key is in contact with the lock and then press the button and wait until the light goes out for it to unlock. The garage has had an auto electrician out who was useless and said they didnt know what it was then they have had a locksmith out who says the key fob is absaloutely fine and suggested it was a bad earth somewhere.. has anyone had similar issue before or known this to be an issue and is it going to be a massive headache! Any advice much appreciated!

Have a read of this.

Check your batteries in the fob, Then check the RF receiver.

https://www.landyzone.co.uk/land-rover/handy-buying-alarm-info.311291/

Cheers