CKEditor preview source dialog in Web Content displays not properly

• Type: Bug
• Status: Verified
• Resolution: Unresolved
• Affects Version/s: Master
• Fix Version/s: None
• Component/s: CKEditor
• Labels: None
• Fix Priority: 2

Steps to Reproduce:

1. Go to Web Content.
2. Add a content.
3. In content field, click Source button in ckeditor toolbar to go to source view.
4. Type "<p>test</p>".
5. Click the Expand icon next to the Source button to preview source.

Expected Results:
Preview source dialog displays properly.

Actual Results:
When the dialog opens, the OK button has border around it automatically even though it's not clicked.

Additional results on different browsers:
Chrome: A redundant scroll bar displays even though all text display.

Firefox: There is an extra white space at the right side of the dialog.

Reproduced on:
Tomcat 9.0.37 + MySQL 5.7. Portal master DXP GIT ID: a6542fe6c2e05052e83df0ba1aabd5e4b8aa1e36.