I don't know what has happened here. Changes have appeared which I did not intend to make including height and roof shapes.
I have deleted tags which are incorrect and created by me using a new changeset.
Thanks for noticing and sorry for this error.
Regards
Tony

That was an unexpected effect of changing the JOSM preset of Public Footpath from 'Simple Marked Footpath' to "Simple unmarked footpath". It changed the highway=footway to the new value I entered "Simple unmarked footpath". I shall revert this tag to highway=footway.