Unable to save birthdays for contacts on local phone account

Summary

When I try to save a contact on the Local phone account, then I am unable to specify the birthday.

This problem does not appear when I select a "/e/ Address book" or a nextcloud powered "WebDAV Address book" for storing the contact.

Steps to reproduce

1. Start the contacts app
2. Click on the "create new contact"-icon
3. Click on "Saving to"
4. Select "Local phone account"
5. Click on "More fields"

What is the current behavior?

There does not appear an entry field for the birthday.

What is the expected correct behavior?

I would expect that I am able to specify a birthday for a contact.