Nesting a Structure in another Structure results in a 'Cannot parse value'

This is a regression. Tested in //UE4/Release-4.27 CL#18319896

Nesting a Structure in another Structure results in a 'Cannot parse value' until the data value is updated. If the second structure is added to a data table; updating the first structure can result in the data entered into the data table being lost.

1. Create or open any project
2. Make a Structure named Struct_A
3. Make a Structure named Struct_B
4. Add a variable to Struct_B
5. Set the variable type to Struct_A
6. Check the icon next to the Add Variable button

Expected Results:
The icon has a green check mark and the tool tip says 'Good to Go'

Actual Results:
There is a red minus symbol and the tool tip says 'Cannot parse value'