Hi,
https://www.openstreetmap.org/way/519138147 is not a riding centre (leisure=horse_riding), it is just a riding arena and should be tagged leisure=pitch + sport=equestrian .Compare https://wiki.openstreetmap.org/wiki/How_to_map_a#Riding_centre_(equestrian) and https://www.openstreetmap.org/way/436845393 . In JOSM you can use the preset for sport=equestrian.