Steps to reproduce
- visit http://localhost:8181/wiki/Middle_English on the Vector desktop site with reference previews enabled.
- Hover over "".
- In the reference preview that appears, hover over "".
- Reference preview should remain unchanged.
- Reference preview disappears.
- Browser version: Chromium v71.0.3578.98
- OS version: Ubuntu v18.10
- Device model: Desktop
- Device language: English
- Git commit: fb56a2e