SharePoint List - New Item is Missing Configure Layout Button

For anyone running into the same issue, here is the solution I found. I couldn't find this anywhere else on the internet.

I have a form created in 2023, and the list form (Add new item) was working one month ago, then randomly changed to a single-column layout with the Configure layout option missing as above.

IT struggled to identify the issue and was hesitant to open a Microsoft ticket without being able to reproduce it. We only found one discrepancy in the List Settings. Under the General Settings section of a test list made in 2025, there is an option for Form settings available that was not present in the list with the issue:

IT identified that the changed list form was a Power App in the background, however I had not made this configuration and the app was not available in the My apps section of Power Apps.

I searched how to disconnect a Power App from a list form in Lists, and saw that the setting was in this Form settings area that I couldn't access. What I did was copy the URL for Rating settings and change "Ratings" in the URL to "Form", and it took me to the correct page:

I changed the Form Options to "Use the default SharePoint form", saved, and my list form was magically fixed.

Of course if you have this issue with a newer list, that Form settings link may just be visible for you with no other complications.