Heya, even if this path is blocked on the ground, it still exists as a legal right of way (it’s on the definitive map of rights of way for the area), so should be mapped.

If it’s blocked in reality, that needs to be reported to the council’s rights of way department: go to https://www.cumberland.gov.uk/parks-culture-and-leisure/countryside-access and click ‘Make an enquiry about public rights of way’