My 2018 Explorer has the same problem. My dealer says that many, many Explorers have this problem. Perhaps most of them. They said it is an issue with the design, the attachments are simply not strong enough to hold onto the rails. My Explorer has 38,000 miles. They told me to contact Ford Customer Service to get authorization, which I did today. I have a vmail from Ford, hoping to connect with them tomorrow.
I drove Ford pickups for years until one of them had an a transmission problem that Ford could not fix in spite of multiple attempts. I thought they should replace it, but they refused. I switched to Chevy for the several more trucks, then a Toyota Tundra, then another Chevy. When I started shopping again a year ago, my brother convinced me to give Ford another chance. I hope I’m not sorry. I will post again on this topic to let you know how it turns out.
At least its releasing from the back and not the other way around! That'd be wild coming loose from the front. The image doesn't look like there is any actual attachment point at all- is it just a pressfit, or is there a tab of some sort that's snapped off?
I tried new snaps, new cap parts, glue, epoxy, tape ... nothing worked! So since the dealer/Ford had no other alternatives, I said "what the hell, screw it; and I did. Yes that's right I screwed it. Two 1 1/2 inch long black anodized drywall screws, one in the front (about 3 inches back from the front tip) and one in the back (about 3 inches before the end of the cap) and DANG ... problem solved. Seriously, it works; now it ain't pretty, but if you use the black screws, it's hardly noticeable.