Steps To Reproduce

• Add an upload field for assets to a dialog (can be a content app dialog or a page dialog - I've attached a sample field)
• Open this dialog
• Upload an asset to this field
• Save the Dialog
• Reopen the dialog
• Click on the delete button the field (the small garbage can icon)
• Save the dialog
• Reopen the dialog yet again

Expected Result
The upload field is blank, the old image was successfully removed.

Actual Result
You will see that the image was never deleted, it is still there in the field.

Additional Notes
The image will be removed successfully if you do not save the dialog.
Happens on page dialogs and content app dialogs.