Merged AnimBlueprint with C++ parent class is corrupted

I merged (among others) an animation blueprint from an Unreal 4 project to an Unreal 5 one. The animation blueprint became corrupted, but my best guess is that it’s because it had a C++ parent class.
Now I’ve reimplemented the parent class, but I still have to tell the animation blueprint where to find it, ~reparent, but without being able to open the animation itself, I don’t know how to do it.
Any ideas? Or could it be that something else causes the corruption?

(Not copy error, I’ve tried multiple times with same result, and other assets didn’t have any problem like that)