Animation Montage won't play every time I restart the project until a recompilation

Tests are operated with the starter pack on UE5.0.3.
The animation montage setup is here:


And the situation is like his:

As you can see, if I open the animation blueprint, compile and save it again without any changes. It works as expected.
But it’ll happen again after I restart the project.
I feel like it’s something related to a weak reference or failed loading.
Epic people, pay some attention here, please.

I’ll report it as a bug

Good news, it will be fixed in 5.1
Unreal Engine Issues and Bug Tracker (UE-162984)