Hi,
The following areas which you tagged with leisure=horse_riding (equestrian center) don't look like equestrian centers:
https://www.openstreetmap.org/way/1451478266
https://www.openstreetmap.org/way/1454751182
https://www.openstreetmap.org/way/1454763484
https://www.openstreetmap.org/way/1454763482
https://www.openstreetmap.org/way/1454763483
The first four are propaböy round pens or riding arenas; they are usually tagged with leisure=pitch + sport=equestrian, exaple: https://www.openstreetmap.org/way/881795829#.
I don't know what the 5th area represents, perhaps it is a paddock (see tag landuse=animal_keeping).

Here are some exaples of equestrian centers in OSM:
https://www.openstreetmap.org/way/1211183284
https://www.openstreetmap.org/way/1206456651
https://www.openstreetmap.org/way/1087585920
See also:
https://wiki.openstreetmap.org/wiki/How_to_map_a#Riding_centre_(equestrian)