Glossary terms rendered into button links

How to reproduce

• Create a glossary with the term "start"
• Embed glossary in course
• Add a test to the course and publish
• Open course with a user that has set his language to EN
• Set glossary mode to highlight terms in content
• Go to test course element
• Hover over start button
  => glossary description appears
• click on button
  => some markup appears on button