Extending Business Central 16.0's "Sales Line Type" enum

I'm presently working on BC 16.0.

You can see below that I am extending a "Sales Line Type" enum and adding a new value to it, same as in BC 16.0 option field is replaced with enum.

However, when I look at the "Sale Line" table, the field Type is an option rather than an enum.

Therefore, the value I added to the enum is hidden.

How can "Sales Line Type" be extended? Am I performing incorrectly?