"Domain already exists" error is returned in ArcGIS Field Maps when a layer is added twice to a web map and a '.' is present in the alias of the feature layer.

Additional Information

Workaround

To mitigate the issue, either do not place a '.' in the alias or rename the alias in ArcGIS Online and remake the domain list.

These are the steps to fix the issue in ArcGIS Online:

1. Go to the item details of the feature layer with the issue.
2. Select the layer in the feature layer that contains a '.'.
3. Rename the layer (at the top of the page) and remove '.' (use '_' for example).
4. Navigate to the Data tab of the feature layer.
5. Navigate to the field with the domain.
6. Edit the List Of Values and delete the list.
7. Remake the list by choosing Create List > Generate List.
8. Refresh and save the associated web map. The issue is resolved in ArcGIS Field Maps.

Steps to Reproduce