CoreData: error: CoreData: error: Row (pk = 1) for entity 'MergeRequest' is missing mandatory text data for property 'id'

I'm converting my app to use SwiftData. I have a class called MergeRequest which everytime I insert it into the modelContext it fails with the following error:

CoreData: error: CoreData: error: Row (pk = 1) for entity 'MergeRequest' is missing mandatory text data for property 'id'

CoreData: error: CoreData: error: Row (pk = 2) for entity 'MergeRequest' is missing mandatory text data for property 'id'

(... repeated for each inserted item)

When I print the id before inserting the class does have a coredata generated id.

PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: x-coredata:///MergeRequest/t5B3316FC-DBE0-4440-88E5-8EDFBA7E856A3), implementation: SwiftData.PersistentIdentifierImplementation)

This is where I insert the model: https://github.com/StefKors/GitLab/blob/cb4c1ef6dec616d5ac146d712658496095c82243/Shared/UserInterface/UserInterface.swift#L137

And this is the full model class: https://github.com/StefKors/GitLab/blob/cb4c1ef6dec616d5ac146d712658496095c82243/Shared/UserInterface/SwiftData/MergeRequest.swift

What I don't get is why does this error happen while it does have an id. Is there some debugging I can do to get more information?