Steps to reproduce:

1. Log in to back office.
2. Go to Content / Content structure.
3. Start creating a new Article content.
4. Fill in 'Intro' input with some random strings for example 2 rows.
5. Mark written strings.
6. Click on 'Bulleted List' button (do not expand Bulleted List dropdown, just click on the button).
7. Verify added Bulleted List option right next to the strings. 

Actual result:

See attached screenshot and watch gif please: https://recordit.co/2FXdBMxVqR

• Bulleted List is formatted to 'Circle'.
• On create/edit an Article form selected Bulleted List is displayed incorrectly
• On preview an Article with richtext field, selected default Bulleted List is displayed properly

Expected result:

• Bulleted List by default should be formatted to 'Disc'.
• Properly displayed selected default option of Bulleted List on create/edit an Article content.

Note:
Numbered List works properly (no investigation / changes needed).