Steps to reproduce:
1. Create a new landing page,
2. Add a schedule block,
3. Select a schedule block,
4. Click on + icon (Add content),
5. Select a content,
6. Confirm selection and close the UDW.
The schedule block preview is not rendered.
The schedule block preview is rendered.
Remarks: It does not occur if something is changed in settings (name, template) before adding content (that's why it wasn't detected by automated suite).