Content Security Policy (CSP) and image inside the post

I have no problems with posting and inserting images, but have strange behaviour of my server.

CSP prefer “self” images, scripts etc.

When I insert the image to the post, it isn’t displayed on the post edit page (get error about CSP in browser console - screen below) - but the image is inserted. However, when I close the post edit page and go back to this edit page again, the image is displayed (and no error in the console).


My CSP setting is: img-src data: ‘self’

What should I chage in CSP, so the image is displayed just after inserting it to the post?
I have no problems with Featured Image.

You’ll need to add support for data: uris as the admin interface uses a base64 format of the image when it’s uploaded to prevent layout shifting and flashing

Thanks, but I am not sure what to add.
Now, I have this:

img-src data: ‘self’