ActorActionUtility / AssetActionUtility use SStructureDetailsView to show dialog for editing function's parameter ( FBlutilityMenuExtensions::CreateBlutilityActionsMenu ).
But SStructureDetailsView does NOT work correctly if the target parameter is struct, so user can NOT edit the struct parameter using the dialog.
The following thread talks about the problem of SStructureDetailsView, but it has not been solved yet.
expect : Can edit the struct parameter
result : Can NOT edit
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-74870 in the post.