The uploaded image is not saved when creating a content with a document blueprint

[nhudinh0309]

Which Umbraco version are you using? (Please write the exact version, example: 10.1.0)

15.0.0-rc4

Bug summary

I have a document blueprint that includes an uploaded image. When I create content using this blueprint and click the 'Save' button, the uploaded image disappears.
This issue happens in v13 also.

Specifics

No response

Steps to reproduce

1. Create a document blueprint with an uploaded image
2. Create a new content with the document blueprint
3. Enter the content name and click the "Save" or "Save and Publish" button

Expected result / actual result

The new content should be created with an uploaded image. Currently there is no image after clicking "Save" or "Save and Publish" button

Uploading DocumentBluePrintWithImage.mp4…