permanent bugs with sructures in BP

I have a variable with type myStrucure in 3PCharactr BP.
After i had made some changes in that structure this variable disappeared. If i try to create a new variable with the same name i get an error “is used by another variable”. How can I solve this issue? I can`t make a variable with another name because it used in dozens BP.

And another annoying bug - loosing connections between structure and another nodes in BP after the project reopening. As I know it’s wide spreaded issue. Is Epic going to fix it?