For simplicity's sake, here is a generic example:
I have a water main feature class. I add it to a map and set a definition query to only show active mains.
In the same map, I add the same water main feature class as a separate layer and set a definition query to only show abandoned mains.
I publish this map as a feature layer to Portal.
In Portal, I share this feature layer with my distributed collaboration so that a copy is made in ArcGIS Online.
The layer fails to synchronize because I have two layers referencing the same feature class.
My idea is to make a change to distributed collaborations that would allow this service to be shared as a copy to ArcGIS Online, even though both layers are referencing the same enterprise feature class.