Ice cream is very fragile because it is sensitive to temperature change. It starts to melt at any temperature above -18 degrees C. Once ice cream starts to melt, even slightly, it is very icy when re-frozen.
Shelves on a freezer door are the worst parts of the freezer for ice cream. Not only do they get the greatest exposure to room temperature when opened and therefore considerable temperature fluctuation but even when the freezer is closed, the shelves are the furthest away from the chilled cold air vent.
My freezer door registers -10 degrees C. This will destroy your ice cream over time, no matter how well it was made. If you end up leaving ice cream on the door, you will need to use it over a week or two. After that, it won’t be as good as when you first bought it.
Leave the door for frozen fruit and vegies. These items can withstand melting and re-freezing much better than ice cream.