CKEditor does not reapply styles

[steveooo]

Hello,

I am using custom styles:

CKEDITOR.stylesSet.add('mystyles', [
    { name: 'Box', element: 'div', attributes: { 'class': 'box' } },
    { name: 'Subheader', element: ['h1', 'h2', 'h3', 'h4', 'h5', 'h6'], attributes: { 'class': 'subheader' } },
    { name: 'No margin bottom', element: ['h1', 'h2', 'h3', 'h4', 'h5', 'h6'], attributes: { 'class': 'no-margin-bottom' } },
    { name: 'Intro nav', element: ['ul', 'ol'], attributes: { 'class': 'intro-navigation' } },
]);

The thing is: I see my custom styling in the editor (via contents.css) and my styles are selectable and savable.

So I style text and save and it works.

On reopening the styles won't apply, even if it was successfully saved (right HTML in database), so when I then save, all styles are gone.

Am I doing something wrong?

[BitPoet]

Have you tried disabling ACF in the field's settings? If disabling ACF makes it work, you'll probably have to add rules for the elements and classes in your custom styles in the Extra Allowed Content field.

[steveooo]

Sorry, it still does not work by disabling ACF. Any other ideas?