I ride along common lane bridleway. Stop at the Cross section. And there is big sign unfortunately I can't add photos here. Its access for little Munden estate farm.

There is massive sign by landowner saying this is not footpath and is private land. I ride this section all the time

I don't where you get information I have walked and cycled near this section I even have photos and written information from local horse rider, the section is impassable and fallen into the river.

This a bridleway not a footpath