Why it happens (according to my observation), the ear wing (I guess it is the soft rubbery part that surrounds the buds) gets dislodged from it's space, just make sure it is properly aligned. And full proof plan is, what I told earlier, after placing it inside, give it a light push and a nudge or jiggle it slightly like really soft. It will make contact. Also sometimes those golden metal contacts get covered with oil or wax.
Its software issue as well not just connection issue, even I face this with my buds 3 pro.. But at least I know how to do troubleshooting initially I was worried but obviously this is not expected from Samsung.
