If you created a similar BP and it didn’t have the problem, then I would say the file is corrupt somehow/somewhere. I’ve experienced that with corrupt files/BP’s, simply deleting the BP and creating a new one with the same name does not work. For whatever reason, I’ve had to create a new blueprint with a different name then inject the code. It’s a headache but that’s how I’ve had to deal with corrupt files in the past.
NOTE: There have also been times when the file path itself (the folder the file is in) was corrupt as well so I needed to create a new folder with a different name and put the new BP with a different name in there. If your “test” BP you just made was in the same file path (folder location) as the one you are having problems with, then I wouldn’t be concerned about the path being corrupt but thought I would mention it.