WebApp: form change - formfield mapping should listed one to one

What is a one sentence summary of your feature request?

WebApp: form change - formfield mapping should listed one to one

Please describe your idea in detail. What is your problem, why do you feel this idea is the best solution, etc.

WebApp: if you change a form, you get an overview of formfields (source & destination) for mapping. If the destination is not there, it is not listet. But there is no empty line in the overview. So the next mapping in the list is given. So it is very confusing, especially if there is a form change from a form with many formfields to a form with just a few ones.
This “feature” is already realised in Win App.

How do you currently solve the challenges you have by not having this feature?

bad overview, if several formfields will be gone