@Manuel_Barrio said it here: Fix naming when creating component variants
The behaviour of adding Variants to components should not change depending on whether the component name is simple or compound (using slashes).
The component naming using slashes should not be used to determine the name and quantity of variants created when using Property > Create Variant.
Adding a Variant to a component should always just add 1 new Variant and leave the component name as the user intended it. It is a much more common use case to add variants to a component already in use than to create a bunch of variants based on a component’s naming structure.
Workaround: cut the component name and replace with a letter, then create the Variant, name the variant property and then paste the original component name back.
As Marco says: “boring”.