boolean widget is broken for now, it is left "display: none" at initialization, if you inspect your HTML you see it is hidden.
Actually boolean widget does not work as expected for now in eea.facetednavigation, we intend to work on this closely even if it is not linked to your problem.
The problem with the boolean widget is that when it appears (;-)) if you check it, it means "True", if it is not checked, it does not mean False, it means widget not taken into account so it displays both True and False results...
For us, it was not the expected behaviour, we wanted to search for True, False, and both. The workaround is to write a plone.indexer that returns "1" when True and "0" when False and a custom vocabulary to use the checkbox widget with it.