With release: 1.0.4b the Extra Action button is staying up, after the action is no longer available.

Can you try with the code in MASTER to see if this is still an issue? I rewrote the extra action bar yesterday m so it might be fixed already

Had to delete and recreate the Extra Action Button bar to get it to work (whatever change you made meant my existing on ceased to work at all).
However once doing so, it's now working perfectly again. Thanks.