I was having the same issue with the frame, it would constantly fall off and I didn’t want to give a faulty card. On my finished card I added a tiny bit of glue to the crease of the frame brackets to give me a tighter hold on the card. Now when I make the cards I make sure to fold the frame brackets slightly past the score line, I glue down one side of each bracket, then I test it to make sure the brackets are tight enough to hold but loose enough I can slide the doors, if it is good I glue down the other sides. Sorry so long, hope this makes sense. 😊