I'm new to ProcessBuilder, have watched the tutorial videos and seminar, yet am not able to do something that should be straightforward (I'm sure i'm doing something dumb).  The scenario is when a custom object1 record is created or edited and its Status picklist value is 'x', then create an instance of another custom object2.   Object2 has a few required fields and PB does a good job of automatically bringing them up in the UI to be assigned.   The problem is after creating Object2 instance, I cannot select the appropriate Object1 instance's field to its corresponding required field; it's simply not available to select.   All of the fields are, however, visible during the initial PB filtering criteria (i.e. Status picklist value filter), but all fields are not available when attempting to assign one of these fields' values.   I guessed this might have been due to a field permissions issue, but that's not the issue.   I also ruled out that formula fields just couldn't be seen here (by rebuilding the field as a text field).  The only other thing to note here is that both custom objects are managed packages, which means I can't change any field definitions, but I can create new fields based on the managed package fields on respective object.

Any insights, please?  Thanks!