[5.x]: Default radio field value isn't applied to existing entries

[thupsi]

What happened?

Description

When creating a radio field with a default value and adding it to an entry's type layout, the default value isn't applied to existing entries.

Steps to reproduce

1. Create a Radio Buttons field with a default value.
2. Add this field to an entry's layout.

Expected behavior

All entries of above type should have the default value applied.

Actual behavior

No radio button is selected.

Craft CMS version

5.4.4

PHP version

No response

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions