Hi and welcome, @Easton! We'd love to learn more about you and your projects in the introductions thread when you have a moment.
I'm sorry you're running into these issues. To confirm, you clicked the preview button again after publishing? I would expect this error if you tried to refresh the same draft preview you were working with previously but the published form preview sounds like it should work.
This could possibly indicate that your form is closed: https://docs.getodk.org/central-forms/#managing-form-lifecycle
Did you assign the new form to the App User(s) you used to configure the tablets? https://docs.getodk.org/central-projects/#central-projects-form-access This is a step I often forget and we are working on a smoother workflow there.
Are you self-hosting Central?