With the Table of Contents config enabled, the top tabs are obscured on pages with max-width set (i.e. those specified by $wgVectorMaxWidthOptions and having body.skin-vector-disable-max-width).
This is with Vector version 7eb818543e78990f6ca62827ae61b6999448b084.
The following screenshots are from /index.php?title=Test&action=history.
With $wgVectorTableOfContents = false; | With $wgVectorTableOfContents = true; | |
ToC open: | This is the error. | |
ToC closed: | ||
Bug originally found by @TheresNoTime in T307725#7930783.