Cannot adjust cluster size range in Map Viewer

[EJSlager_kcgis]

I'm working on clustering point data in Map Viewer, and I am unable to adjust the cluster size range with the slider in the configuration panel. 

Here are two screen shots where I have changed the size range settings, but the size of the clustered points does not change: 

The layers were uploaded to AGO from Pro, where the clustering was initially configured. However, if I remove clustering and add the clustering directly in AGO, the same problem occurs. Oddly, another layer in the map that has clusters (added a previous date by the same metho) can be adjusted with the size range slider. The cluster symbology also does not get added to the legend for the affected layer, whereas it does on the other layer. 

I can't find any differences in the way the two layers are configured, but I feel like I must be missing a setting. Any ideas for where to look, or for other workarounds? The cluster radius and scale threshold sliders do have the expected effect. 

[EJSlager_kcgis · Accepted solution]

I overwrote the hosted feature layer, this time disabling clustering in ArcPro before publishing the web layer. Now, I'm able to add clustering to the hosted feature layer and adjust the cluster sizing using the setting pane in Web Viewer.

Leaving the original post in case others run into the same issue, but admins please feel free to delete.