Error with On-Demand Resources

I'm trying to set up an app to be able to download asset bundles as On-Demand Resources
I've followed this guide: https://docs.unity3d.com/Manual/AppThinning.html

And the resource packages are uploaded with the app to the App store and I can see that it has the packages, but when testing it through TestFlight it is unable to download anything.
Here's the error:

Code (CSharp):

1. Exception: ODR request failed:
2.  
3. at DownloadODR+<DownloadResource>c__Iterator0.MoveNext () [0x00000] in <filename unknown>:0
4.  
5. at DownloadODR+<DownloadResource>c__Iterator0.MoveNext () [0x00000] in <filename unknown>:0
6.  
7. at System.Collections.Generic.List`1[T].AddEnumerable (IEnumerable`1 enumerable) [0x00000] in <filename unknown>:0
8.  
9. at UnityEngine.SetupCoroutine.InvokeMoveNext (IEnumerator enumerator, IntPtr returnValueAddress) [0x00000] in <filename unknown>:0
10.  
11. at System.Threading.Interlocked.CompareExchange[T] (.T& location1, .T value, .T comparand) [0x00000] in <filename unknown>:0
12.  
13. at System.Threading.Interlocked.CompareExchange[T] (.T& location1, .T value, .T comparand) [0x00000] in <filename unknown>:0
14.  
15. System.Threading.Interlocked:CompareExchange(T&, T, T)
16.  
17. System.Threading.Interlocked:CompareExchange(T&, T, T)

I tried the example that is posted for the assetbundlemanager on bitbucket and that doesn't work either.