You are probably on the wrong tab. Check the tab.

Remember our tab selections are "sticky".

You are probably on the wrong tab. Check the tab.

Remember our tab selections are "sticky".

so some session state is clearly confused and all my tag searches are stuck onto questions with bounties only.

edit: You selected that tab so it stays selected -- as I said. It's "sticky". So you are browsing bountied questions only until you select another tab.