Product field readonly

Below code does not make the field read only when creating fields via code.
What’s misisng?
The other options such as MultiCulture etc… are working fine.

return new FieldDefinition
Editable = false

Litium version: 7.2.0

It might be a bug then let me check that and get back to you

Yes I tried that out with 2 new fields one with value set to true and one with the opposite and the outcome of both where ReadOnly = No.
Can you report a bug on this please?