I am testing a two-weight cuckoo clock I repaired/restored. It works fine, however, I notice that the cuckoo bird’s door pops out a bit at the warning. It can easily be pushed shut with no restriction. After striking, the door closes with tension keeping it in place. I am a beginner, and not sure what, if any, adjustment needs to be made. It has a rack and snail. My other cuckoo clock, which has a count wheel (which was worked on by someone else) does not do this at the warning. Any advice or suggestions are appreciated. Thanks.