Enums in BP Structures display as Byte on Struct save

When an enum variable is added to a BP struct, saving the struct causes the enum to display its type as a Byte rather than the specified enum.

Regression:
Yes - This behavior does not occur in 4.16.3 (CL 3561208)

1. Open UE4 Editor (any project)
2. Add BP structure
3. Set MemberVar_0's type to Anim Phys Sim Space Type (first option in Enum dropdown)
4. Save the structure

Result:
Variable type changes from Anim Phys Sim Space to Byte

Expected:
Variable type remains after saving the struct