Hi,
you removed the building tag from https://www.openstreetmap.org/way/646104497 although it is a building (see https://www.seabrookisland.com/club-life/equestrian/). Tag leisure=horse_riding is not appropriate for small buildings, it is for complete ridnig centers. In this case the riding center is tagged as a sports center: https://www.openstreetmap.org/way/1125527582. It should not be mapped twice.