Billboard is moving from its position when zoomout and in

I have a billboard collection and when I try to zoom out or zoom in the position of billboard is displaying at wrong place and also even when I provide 0 altitude to position property it still has some altitude added to it

Can you let me know what I am doing wrong?

Attaching code snippet for your reference

id: id,
position: Cesium.Cartesian3.fromDegrees(long, lat, 0),
show : true,
distanceDisplayCondition : new Cesium.DistanceDisplayCondition(1000.0, 30000.0),
verticalOrigin: Cesium.VerticalOrigin.BOTTOM

You can use: - heightReference: Cesium.HeightReference.CLAMP_TO_GROUND

@Shashi Thanks for your reply!

But I need it to be at certain Altitude not on ground surface

Have you tried : - heightReference: Cesium.HeightReference.RELATIVE_TO_GROUND

Yes still the same