The fixed variable A is changed to a value range variable. This is automatically recognized by default. The fact that the change icon is still displayed in the tree is due to other table changes.
Check the assignment by opening the list of a value range field. The value range has to contain all possible values.
Select different rows in the left table and check whether the value range value is adjusted accordingly in the right table.
If all assignments are correct, click on Confirm all assignments [Verify all mappings]
.