Chris, I have a 2011 4/4. & some years ago occasionally had that problem.
I changed the key to the supplied spare & have not had the problem since. On my 4/4 you have to put your head in the passenger footwell & look up to see the flashing immobiliser light. (Helps if done when dark) I can’t find the info at the moment as not at home. Others will know, but how the flashes respond when operating the key may give you a clue to what’s going on.
Good luck.
