@Christopher_Reeves, or anyone viewing this, not sure if this will help, and I hope this is not the same solution for you. In the following links I had a very similar issue after a long chain of events, most of the issues caused by me.
After replicating a dataset to a new pool, then an OS upgrade, and promoting cloned snapshots I ultimately had to destroy the pool and rebuild but, I was able to save a lot of data with an SMB ZIP file of the dataset I wanted to save.
Replication would have been the best option but, my replication target had encryption when my source did not and threw a wrench in to the wheels.
Here are the links to the posts:
Again, not sure if any of this will assist but I hope it may as it is very similar to what I experienced. Hopefully you can get this resolved without a major rework.