@doubletrout,
Instead of using that icon (I’m digging into whether or not we know about this issue, more on that when I get more info), you can open the Shields panel (lion icon in the address bar) and enable JS via the Shields toggle. Note that settings configured in the Shields panel are site-specific, so if you have JS disabled by default (Settings --> Shields) you can change the setting for specific sites without affecting default behavior.