Steps:

1. Click Page/Site
2. Click and select Landing Page
3. Fill required fields and add Embed block
4. Embed for example new Landing Page using COTF, place it in Home
5. Publish
6. Send embedded LP to Trash.
7. Go back to the edit mode of created landing page with embed block
8. Go to setting of Embed block

Actual result:

See attachment, please. Block preview displays that _ Selected Content is deleted or unavailable_ but in block settings content is still visible.

Expected result:

Settings should be empty or there should be an information about unavailable content.