I found that when a map service containing polygons with label is published from ArcGIS server, the labels appears duplicated as when using the below cesium code
It looks like the multiple labels are a side effect from how we tile the imagery. We ask the map server for the imagery in pieces, and it’s returning pieces with a label on each part.
Here’s a visualization:
The yellow outlines are the boundaries of the tiles. My guess is that other maps like leaflet just request one image that spans the whole view.
Sorry, I don’t have a workaround for this. I’m guessing we request the imagery like this so it works better in our 3D view where it’s not possible to grab just 1 rectangular extent.