The box comes with a check mark in it.  You can click that box to remove the check mark.

 

If I uncheck that box, the 2021 return won’t “create” in the system.  Some moron developer made checking the box mandatory if it is an existing client.  I was a developer for OneSource tax software, and this error would never have made it through Thomson-Reuters testing.

If I uncheck the box, it removes any link to prior year return and creates a nice fresh clean unclutter with prior year data return. I thought that was what you wanted.
If you check the profile to roll forward, then it puts the check box it.
I do not see any moron at work in the programming that I am observing.

When I am online with ProConnect and I uncheck the box for an existing client,it will not create a 2021 return for that client at all.  As soon as I uncheck the box, the button to create return goes gray, and it becomes impossible to even click on that button.  I’ve tried it 4 times.