Nature reserves don't appear on the map

I am a new user of OSM, and I would like to add as many nature reserves as I can (in Wallonie).
After drawing a reserve in the editing mode and saving, I can clearly see it in this mode, but not on the ‘public’ map. Sometimes, I can see some fragments of the border line when I zoom strongly but never more…
How could I solve this problem ?
Thank you !

https://www.openstreetmap.org/way/631605843#map=15/50.0981/4.6600 exists in the public map (the orange area) and is also present in at least of the three sample renderings on the main web site.

Only the vector map is the OSM map. The rendered images serve various purpose, but none of them contain all the information that is in the actual map.

It is most likely that you didn’t wait long enough for the map tiles to be re-rendered, or you didn’t properly flush your browser cache.

However, if you can specifically identify an object that is failing to render, and the rendering on which it fails to render, we could probably have a go at working out why that is.

maybe because there are 2 ‘different’ items you mapped ? →
https://www.openstreetmap.org/#map=15/50.0980/4.6576
https://www.openstreetmap.org/way/97716522#map=15/50.0988/4.6556

Thank you for your help !
Now I can see the items I created.

Using an editor, or by ticking the data checkbox on the layers tab of the web interface.