Nested structs do not expand in the details panel whenever opening it in the full Blueprint Editor.
Tested in 4.20.3 (CL - 4369336), 4.21.2 (CL - 4753647), 4.22.1 (CL - 6063286), 4.23 (CL - 6684273)
Expected: The Standard attack type map should be expandable
Result: The option to expand is not present
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-75493 in the post.