Hi, we are also facing the same issue but in our CSV there are no Lat/Lan details available, is there any possibility of adding those in the ArcGIS portal without Lat/Lan details to covert into the feature layer.
As we all know that there is an option in ArcGIS online without Lat/Lan details we can add as an item in a web map and create as a feature layer.
But we required to be published in ArcGIS Portal, is there any way to publish. Below is error when we try to add from file through web map.