does anyone know how to resolve an issue with ArcGIS online configuring a custom pop-up? I'm not able to save it even when I update the layer and keeps converting back to its default.
Have you tried to remove the popup first and save the web map and then configure the popup for that layer again?
Are you using Arcade?
Is your layer hosted in ArcGIS Online or ArcGIS Server?
Can you post an example of what you're attempting to put in the custom pop up?
Retrieving data ...