Infiniti Q45 door locks

I have owned six Q45s, 1992, 1994, 2000, 2002,2005. Every one of them has this problem:the driver’s door occasionally locks itself when it is closed. Not the locking system because the other doors stay open (if they were open before, otherwise I’m locked out). Happens maybe once a month. Dealer “cannot reproduce the problem” but subtly implies that I accidentally press the key fob lock button.