I created a list and then customized the input form. What I didn't realize is that once I customize the form, that becomes the only way I can update the form correctly.
Is there anyway to "Uncustomize" a form?
The specific steps will change depending on how the form was customized and what version of SharePoint you're using. But in general, this should work for common scenarios:
Go to list settings --> form settings, and select "use the default SharePoint form"