Steps to reproduce:
- On the clean 3.1.0-ee install create a new article.
- Copy a text paragraph from any PDF/Word document that contains the bold text.
- Try to unbold text in the pasted paragraph in the Online Editor.
The selected text is unbolded
The selected text is still bold
Most likely it is caused by the fact that `b` tag is used for the pasted text instead of `strong`: