u/Green_Ad2295

I have a permanent crown on my back right bottom tooth. This crown has come out at least 4 times since I’ve gotten it redone about 2 years ago. My crown has come out this latest time about ago after being recemented in January. I don’t have insurance and can’t afford to pay out of pocket. My questions are, is it possible for the stump to move? When I just brushed my teeth, the positioning feels off. And is it possible to get a cavity on the stump?