I had this issue too. Fixed with the renaming trick mentionned above.
I noticed something else in 4.17 : when editing the structs, i click save button, all variables types are changed to base types struct/int/string, etc. A vector and a transform were changed to struct. Then i close this window, launch the game, and then open the struct again, it goes back to normal. Opening the struct without launching the game still displays the wrong types on variables.