One short section of footway is tagged as both foot=permissive and designation=public_footpath, which seems to be contradictory.

The PRoW data for Kent/Sevenoaks Urban suggests that this is part of public footpath SU30, but OSM currently has this path following a different alignment.

As this is all on National Trust land, hopefully it's something you can check and correct more easily than me.

https://www.openstreetmap.org/way/1134826307
https://osm.mathmos.net/prow/progress/kent/sevenoaks/sevenoaks-urban/