Have you tried renaming the struct(s) and then cleaned up all redirectors (from the right-click-menu)?
I had a similar problem and I believe it was solved doing something like that, after which I could rename the struct back to its old name (and clean up redirectors again).
After which I think I had to restore ALL affected blueprints from a backup to have them reference back to the original struct asset names afterwards (since otherwise they will still try to reference the bad struct names) It was a bit of a hassle.
This could possibly help, but im not sure. You could give it a try, and always keep many backups.