The personal links and the page tabs (Page, Talk etc.) are reversed in the Vector skin when the UI language is RTL. This is a recent regression. It is already deployed in Commons. Example: https://commons.wikimedia.org/wiki/Main_Page?uselang=he .
Version: unspecified
Severity: blocker
See Also:
T48947: Vector: Horizontal nav elements should be flipped with CSS instead of in HTML
T56673: LESS compiler should preserve the position of CSSMin / CSSJanus annotations