Hi, I don't know if this will help you, but recently I also had a CKEDitor problem (PW v: 3.0.165, browsers (64bit): Firefox v: 80.0.1 Chrome v: 85.0.4183.102) and searching solution for my problem I played with CKEditor and using the setting below I didn't experienced the reported problem. My Block Style settings:
{ name: 'Blue Title', element: 'h2', styles: { 'color': 'Blue' } },
{ name: 'Red Title' , element: 'h3', styles: { 'color': 'Red' } }
which I appended to wire/modules/Inputfield/InputfieldCKEditor/mystyles.js:
/**
* mystyles.js
*
* This file may be used when you have "Styles" as one of the items in your toolbar.
*
* For a more comprehensive example, see the file ./ckeditor-[version]/styles.js
*
*/
CKEDITOR.stylesSet.add( 'mystyles', [
{ name: 'Inline Code', element: 'code' },
{ name: 'Inline Quotation', element: 'q' },
{ name: 'Left Aligned Photo', element: 'img', attributes: { 'class': 'align_left' } },
{ name: 'Right Aligned Photo', element: 'img', attributes: { 'class': 'align_right' } },
{ name: 'Centered Photo', element: 'img', attributes: { 'class': 'align_center' } },
{ name: 'Small', element: 'small' },
{ name: 'Deleted Text', element: 'del' },
{ name: 'Inserted Text', element: 'ins' },
{ name: 'Cited Work', element: 'cite' },
{ name: 'Blue Title', element: 'h2', styles: { 'color': 'Blue' } },
{ name: 'Red Title' , element: 'h3', styles: { 'color': 'Red' } }
] );
Useful link about CKEditor settings: talk/topic/17862-share-your-ckeditor-settings/?tab=comments#comment-156594