Steps to reproduce:

1. Open a private window, resize it to window.innerHeight === 393, window.innerWidth === 1280.
2. Go to https://de.wikipedia.org/wiki/Datei:IAPH_Casas_cueva_Purullena.jpg.
3. Repeatedly click on the tab "Datei".

Expected: Since the tabs are too wide, they should collapse.
Actual: Sometimes the tabs are not collapsed, hiding the title of the page. Triggering a resize always makes them collapse as expected. For some reason I cannot reproduce with the browser console open, so the height seems to be important, too.