A work around is to Insert a Gallery (If not already done)
1. Put the List on the ITEMS of the Gallery1
2. In the ITEM of the Form, put: Gallery1.Selected
3. On the Dropdown Default, put:
If(YourFormName.Mode=FormMode.Edit,Gallery1.Selected.ColumnOnDropdown,"")
4. You can set the AllowedEmptySelection property of the Dropdown to true
Please change Gallery1 to your actual Gallery name
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