Mosaic allows person records without a date of birth when the AGE_ESTIMATED setting is enabled.
We use a database setting called AGE_ESTIMATED that, when set to Y, lets you create person records without a date of birth, usually for unborn children. When this is enabled, you won’t be able to edit some basic details like the DOB.
If you need to disable this setting, just raise a new case online and mention the title of this article.