I've enabled the plugin qgis2web, after getting one WFS layer in to QGIS I started the gis2web plugin. Because it is a WFS layer and I want leaflet to use that WFS I don't check the Encode to JSON option.
The preview shows only the base layer. If I do enable the Encode to JSON option, my layer does show.
I've tried with different WFS-services in QGIS 2.10.0
What am I doing wrong?