Problem with unique value in field

Question

I am trying to set one of the fields in a survey to be unique by following these directions: https://doc.arcgis.com/en/arcgis-online/manage-data/add-unique-constraint.htm. When I check the box for the Field contains unique values, it responds that there are duplicate values.  There where duplicates the first time I tried this, and they were identified in the summary table of top 10 values.  I eliminated the duplicates and now none are listed in the top ten table, but I still get the duplicate error.  I downloaded the data into excel and did a search there for duplicates and none were found.  Any suggestions?

DanCrafton · Answer

No values are blank and there are no sublayers.  I was able to set the same field as unique in a similar survey developed with Survey123 Connect.  I just manually went through all 1000 plus data points in the web based survey and confirmed there are no duplicates.  I attached an excel spreadsheet of the data from the field.

unique field_analysis.xlsx

ZenMasterZeke · Answer

Could any of the values be blanks? Also, the documentation refers to sublayers of hosted feature layers. Also also, maybe Survey123 doesn't recognize the constraint? Not sure about that. Try it with the feature in a web map or other app.

DanCrafton · Answer

Yes, I am using AGOL.  The survey in question was developed with the web based version of Survey123.