Inconsistent and Confusing Tab Menu
When a tab is pinned with Epiphany, it does not have a “Close Tab” button (in the tab context menu) any longer, but a ton of options that hardly anyone needs. Pinned tabs can still be closed by the “Close All Tabs on the Left” button, which can also be triggered from a pinned tab, and which has chaotic consequences, especially when closed tabs are reopened (Ctrl+Shift+T).
Suggestion: Make a clean UI specification about what functionality is actually desired and implement a consistent menu.