Hi Nolan,
Mine did the same thing after a few trips. Check the roller latch on the camper to ensure the screws are tight. If they're not they'll move around and prevent a good connection when the door is closed. If the screws aren't getting a good bite into the wood replace them with longer screws so the roller latch doesn't move around. What you did with the other side is what I did, spread the end piece out a bit for a tighter fit. Since I made these changes I haven't had any issues, but then again, I always travel with a vent or a window slightly open to prevent vacuum issues.