contentSize doesn't work in theme.json file

On WordPress 6.5.2 version, in the theme.json file, I have the following code

  "version": 2,
  "settings": {
    "layout": {
      "contentSize": "800px"

But it doesn’t work if editing any Post or opening Site Editor

Post Editing

Screenshot – Post Editing

Site Editor

Screenshot – Site Editor

Hello @Sergey_Gabrielyan,

Although it is a code development query, I have tested the code on a default WordPress site using the twentytwentyfour theme. I manually made changes to the theme.json file and after saving the file, I cleared the server/page cache and Kinsta CDN cache. The changes were reflected in the “contentSize” value without any issues.

If you haven’t, I suggest clearing also the Site and CDN cache if it’s enabled on your site since .json extensions are served through the Kinsta CDN if it’s enabled.

To clear the CDN Cache - go to WordPress Sites > sitename > CDN > Clear CDN cache).

If clearing the Site and CDN cache doesn’t work, it may be because a plugin active on the site is overriding the value. You might need to temporarily disable other plugins to find which one could be conflicting.

I hope you find this information helpful. :slightly_smiling_face:

Let me know if you have any further questions or concerns.

Hello @Adrian_L. I’ve found the solution, but thank you for responding.

Hi @Sergey_Gabrielyan Glad to know that the issue has been resolved.
If you have questions or issues in the future, please feel free to reach out.

Have a great day!