So recently i had a plug come completely out of the head. the threads didn't appear to be damaged at the time but upon further inspection it wasn't fully threaded into the hole. when i tried to tighten it back down it wouldn't go all the way with out a lot of force. i did this slowly in several attempts, in and out, and think it's seated back right. Is there any cause for this other than being cross threaded to begin with and is there a fix that doesn't require removing the head to re-tap the hole again?