I’m seeing some unexpected behaviour with point clustering in the new Map Viewer in ArcGIS Online, specifically with symbol sizes.
Once clustering is enabled, symbol sizing becomes unreliable, even when all symbols are configured with the same pixel values. One issue is that “Adjust size automatically” appears to be enabled, but no longer works. Without clustering, symbols scale smoothly as you zoom and the legend updates. As soon as clustering is turned on, sizes switch to fixed internal values and the legend stops updating — with no warning that the setting is being ignored.
I’ve also seen individual points from the same dataset and category render at different sizes after clustering is applied, usually after adjusting the size of one sub‑category. The symbol settings still show identical px values, but the map displays different‑sized points. Once this happens, the size difference can persist even when zooming back out.
Some context:
- Happens with multiple datasets (including public data)
- Occurs whether the layer is hosted in AGOL or published from ArcGIS Pro
- No issues visible in the Web Map JSON
From a user point of view, this is hard to trust and hard to explain. Symbol size is a key visual cue, and when identical features render differently — or UI settings silently stop working — it undermines confidence in the map, especially during review and validation in AGOL.
At minimum, it would really help if incompatible settings were clearly disabled or flagged, or if symbol sizing behaved consistently when clustering is enabled.
Expected vs actual behaviour:
Expected: point symbols of the same category and with the same size settings render consistently across scales, and “Adjust size automatically” either works with clustering or is clearly disabled.
Actual: clustering overrides symbol sizing in non‑obvious ways, auto‑scaling stops working without warning, legends don’t update, and identical features can appear at different sizes in the new Map Viewer.
