Radio default not working

I have no idea what I’m doing wrong, but I can’t get the default option to work in my radio field. My code is straight from the docs:

    category:
        label: Category
        type: radio
        default: architecture
        options:
            design: Design
            architecture: Architecture
            photography: Photography
            3d: 3D
            web: Web

…but I get no default value as you can see below:

What am I doing wrong? Thanks!

Is it on an existing page? Had the same issue, but inside a builder field. It worked for me after creating a new entry.

Thank you @jakobgrommas! Mine is in a custom plugin, but the key was “creating a new entry” like you mentioned. It doesn’t work if you add the field after the entry has already been created.

The default only works, when the content file is created the FIRST time.
So I would delete the whole page (directory and all files inside it). Now I can check this problem.

[Added:]
Or I would add a new page. Here I can check the content file.

Thanks @anon77445132. I can’t afford to re-create each page, but will go through and manually click the radio fields for the existing pages. New pages are working just fine as you said.