Hi,
You habe removed the building tag from https://www.openstreetmap.org/way/273996583. Therefore this building will no longer be rendered as a building on the maps. If it is an indoor arena you can use building=riding_hall.
The tag leisure=horse_riding is not appropriate for a single building of a riding centre; it is for the area of the whole riding centre; see example https://www.openstreetmap.org/way/703036885#map=19/53.09237/6.69454&layers=P
See also
https://wiki.openstreetmap.org/wiki/Tag%3Aleisure%3Dhorse_riding
https://wiki.openstreetmap.org/wiki/Tag:building%3Driding_hall