[Flow] _Original classes not generated for singleton typoe classes?

[Christian Loock]

Hello everyone,

I once again encountered a weird issue. Coming back to an old flow 
project of mine, after updating the flow version to 2.2, I get weir errors.

Fatal error: Class 
'VKF\Core\Security\Authentication\AuthenticationProviderManager_Original' not 
found in

If i look into the generated class, it becomes clear that the _Original 
classes is not generated. After doing a little research, I figured out, 
that this was only happening with classes that had thei Flow\Scope set 
to "singleton". Does anybody know if something in this regard has 
changed in a somewhat recent update to Flow and how to solve it, without 
making the classes prototypes?

Cheers,
Chris