2003 Forester tailgate

My Forester is a great little car with about 55,000 miles on it. Lately, just once in awhile, the tailgate won’t unlock with the remote. I just press lock, unlock and it opens just fine. Now today it wont unlock manually or with the remote. The other doors work just fine. Any suggestions on what to look for before I head to the dealer?

It sounds like the lock mechanism is sticking somehow. Whoever works on it will have to get inside the tailgate to see what is going on with it.