I dont get any beebs from mine when looking or unlocking. Normally a beeb is followed by a message on the message centre.
The common ones are a door or bonnet isnt shut properly. thinking about it these would be a high pitch alarm siren. signifying a miss lock.
It could be a sticking ignition barrel switch, this makes the car think the key is in when its not. low screen wash warning, windows not set, the trick is to check the message centre. look at the display as it would give you a better understanding to whats happening.
If you have a owners handbook for it all the message centre commands are explained in the back.
Hope this helps