Hi,
You have removed the building tag from the large building and retagged it as a riding centre. But without a building tag this building will no longer be rendered as a building on the maps. Also the tag leisure=horse_riding is not meant for specific buildings but for the whole riding centre, like here: https://www.openstreetmap.org/way/810083535#map=16/60.6411/17.1114&layers=P
Compare https://wiki.openstreetmap.org/wiki/Tag:leisure%3Dhorse_riding