Text editor paragraph formatting in Dialog Cards can not be used as they keep on flashing/blinking.

Replication:
1. Go to Moodle demo site (https://sandbox.moodledemo.net/).
2. Log in as a Teacher user.
3. Go to any available course, turn editing on.
4. Click "Add an activity or resource" link and select H5P.
5. Click the "Package file / Use the content bank (opens in new window) to manage your H5P files" link.
6. In the new window, click the "Add" button.
7. Select the "Dialog cards" from the list.
8. Scroll down and in the Dialogs section, click the field for "Text".
9. Once the text editor is loaded, type words onto it.
10. Click the "Normal" dropdown (text formatting / paragraph format)
Result: The drop down list keeps on flashing/blinking. It is can not be used.
The only option displayed is "Normal".

Additional:
Other content types such as Accordion contains
Heading 2
Heading 3
Formatted
Normal
for the Paragraph Format dropdown control.