Unable to visualize feature layers in new Map Viewer after applying delete From the Service Definition operation at the Rest Endpoint.

Workaround

In ArcGIS Pro:

• Click Insert > Connection > Add Database > Select FGDB of interest.
• Click View > Catalog Pane > Expand Database > expand FGDB of interest > Add FGBD feature class to the map.
• Click Share > Web Layer > Publish Web layer > Fill out name, tags, and summary > layer type feature and click Publish.

In ArcGIS Online:

• Click newly published hosted feature layer to open item details > click Export Data to FGDB > Fill out name, tags, and summary > Click Export.
• After exporting Data to FGDB > Click Publish in order to Publish FGDB data as a hosted feature layer.
• In ArcGIS Online Create View Layer from newly published hosted feature layer > Fill out name, tags, and summary.
• Click View Layer to open item details page > Scroll down to the top right next to URL and click View.
• In the URL, add admin between rest and services: rest/admin/services.
• Scroll to the bottom and click Delete From Definition.
• In the Delete From Service Definition box, delete all the content (ctrl A + Back space), and paste the deleteFromDefinition parameter for as many layers as you wish > At the bottom, click Delete From Service Definition.
• Open the newly modified View Layer in New Map Viewer, and all layers load properly.

Steps to Reproduce