Hi,
Simply OSMI was reporting the presence of 2 nodes in the same location.
By doing the Merge between nodes one was removed as it was redundant.
Vedi https://resultmaps.neis-one.org/osm-change-viz?c=136818872#21/47.35353/8.51060
I see that you entered the area as "place"
https://www.openstreetmap.org/way/117778756
In this case JOSM reports the omission of the name.
Regards