Hello, and welcome to OSM.

Nice try, but you unfortunately created some damage on the map here.
Some parts of the gardens grossly overlap buildings, and you also destroyed two buildings on Avenue Armand Huysmans/Armand Huysmanslaan, which you split into multiple parts for no reason.
If you want to use the simple editor on the osm.org website, please stay away from the "scissors" button, this is a dangerous action.
I will try to repair as much as I can here.