Symfony version(s) affected: encountered on 4.3

We have a state machine with some transition having multiple "froms":

do-it:
  from: [A, B]
  to: C

Then we have a guard event for this transition, at this point the current marking is e.g. A.

We add a transition blocker.

During apply we see The marking does not enable the transition., where our custom "explanation" from the transition blocker was expected.

I think a bug lies in

https://github.com/symfony/symfony/blob/4.3/src/Symfony/Component/Workflow/Workflow.php#L257-L278

Our current place is "A", but it expects A and B to be set in the marking 🤔

Is this something Petri net specific still?

cc @lyrixx :) maybe im missing it.