Field formatter settings form and AJAX issue (regression on 10.1.x after #857312)

A possible fix, based on EntityDisplayFormBase::multistepAjax.

I can't figure out how to apply this patch. I am on 8.x-3.15.

My line 961 is this:

    ];
  }
  else {
    $form['ft']['id']['#ajax'] = [
      'callback' => 'ds_field_ui_display_overview_multistep_js',
      'wrapper' => 'field-display-overview-wrapper',
    ];
  }

Hi @newswatch, that's correct. This applies cleanly on 3.15, and 3.x-dev, I just tested.
https://git.drupalcode.org/project/ds/-/blob/8.x-3.x/ds.module?ref_type=...
https://git.drupalcode.org/project/ds/-/blob/8.x-3.15/ds.module?ref_type...

Hi Hervé.

I just applied this on a small site. No issues so far.

Now, to apply this to a site that's big and live.

Thank you so much!

This looks pretty major, checking soon

Looks like the right fix, thanks for that. Committed and pushed!