When you have a struct variable that is part of a TMap which is stored in an inherited component, the struct is not editable in the full blueprint editor. It is editable in the data only blueprint editor however.
Regression?: No
This also occurred in 4.15
Branches tested:
4.15.3-3450819+++UE4+Release-4.15
4.16.1-3466753+++UE4+Release-4.16
4.17.0-3515847+++UE4+Dev-Main
Head over to the existing Questions & Answers thread and let us know what's up.