TfL website journey planner returns "buses only" route even though all transport options selected

Hi

There’s an issue on the TfL site, where the journey planner will return a buses only route even though all transport options are selected. Screenshot attached.

Windows 10
Firefox 59.0.2 (64-bit)
DNS based ad-blocking enabled at the router level (similar to Adblock, but no script or other blocking)

Thanks.

There’s some discussion of this issue in