after looking around that the garden got lost as part of the lake. I added it as inner member. But still not visible

everything is back to normal. i imported to JOSM but dont see any problem. .... the last thing i could do is, to import into my PostgrSQL database and check the geometry

Sounds reasonable... So... i added the wikidata-id to the object and removed from the relation (which seems to be deleted now) Nevertheless i do not see the island/garden here at all

Didi it exist twice? Meanwhile i found another relation with taht name, but i am sure it did not exist when i created this one

Why it was deleted?

It is corresponding to the wikidata object https://www.wikidata.org/wiki/Q139913086
Please verify, if it is not connected to Wikidata.

The Jurong Lake Gardens consits of the three gardens
- Chinese Garden
- Japanese Garden
- Lakeside Garden v

see: https://juronglakegardens.nparks.gov.sg/our-gardens/

but nevertheless i do not understand why the greeb island area is not shown.
We can turn it bock to the old way, maybe it was just a missing tag on the way

To me its still not clear, how OSM distinguishes a way between a polyline and a (closed) polygon. Both are "ways". In my job i work daily with geospatial databases but there the differenvce is clear. Anyhow, Wikivoyage/Wikidata has shown it as a polyline only.

The problem was it was not shown as a closed polygon on external maps. Just a line. I was not able to fill it with a color