After fetching my D4 back for some warrantee stuff last week, including iffy unlocking/locking rear doors, it transpires that this is (as of Thursday last week) a known fault.
If you have problems with yours I'd recommend giving your dealer a buzz as they replaced mine and the problem has now vanished.
If you have problems with yours I'd recommend giving your dealer a buzz as they replaced mine and the problem has now vanished.