By "reconnecting" do you mean deleting and re-adding the phone-as-key connection? That can help.
Also search for relevant threads with tips like not having the phone in your back pocket when approaching the car. A thread or two suggested renaming your phone's bluetooth if needed to remove punctuation as in Sixfootwo's phone.
A more extreme tip was to remove unusual punctuation in your contacts' names. That seems an unlikely fix, esp. since the BT key connection is separate from the BT phone/text/audio/contacts connection, although it takes a while to get confidence in whether a change fixes a flakey problem. I'd expect that turning off contact-sync would be an adequate and quicker test of that hypothesis.
One person on TMC had to get a replacement bluetooth module in the driver side B pillar. That should be rare but you could test if the passenger side bluetooth module unlocks the car reliably.