We have observed a problem with inline blocks as properties in lists. The edit mode renders the properties just fine and you are able to enter information as expected. However, the value(s) are not saved. Seen in version 12.28.0 and previous versions.

To reproduce:

1. Open the CMS and enter Admin mode.
2. Create three new block types:
   1. Content type #1. "PhoneNumber" - with two properties: Prefix (string <=255), Number (string <=255)
   2. Content type #2. "Employee" - with two properties: Name (string <=255), Phone (block: PhoneNumber)
   3. Content type #3. "Company" - with two properties: Name (string <=255), Employees (block: Employee - also check the "List"-checkbox.
3. Head back to Edit mode and create a new block of type: Company.
4. Add an Employee and give him/her a name and fill out the fields for Phone (prefix and number)
5. Save and publish the block.
6. Open the same block for edit and expand the list of Employees - the values for Phone (prefix and number) are not there.