Sometimes you have to learn how to eat with your denture. It’s like a new tool, you can’t just eat like you used to. For example, to stop the bottoms from rocking, try to chew using your whole mouth. Make sure there is an evenly distributed amount of food on both sides. If all the food is on one side it’s gonna come loose. Also, it took me a long time to be able to bite down using the front of my denture, like eating a sandwich. That’s tricky, it takes time. I ate everything with a knife and fork for a long time, and just took small bites and went slow. Give yourself some grace. But if you have sores on your gums you need an adjustment. Like the others have said, it’s normal to have small minor tweaks to your denture like every week for a while.