Watford General Hospital has been mapped as a polygon for ~17 years, so adding a duplicate node is unnecesary. The same applies to the duplicate leisure=park nodes which you have added.
https://www.openstreetmap.org/way/7989424

Also, when you use the addr:street tag, this is for the name of the street only. There's documentation on addresses in the UK at https://wiki.openstreetmap.org/wiki/Addresses_in_the_United_Kingdom