GetReferencesToContentItems throws exception after upgrade to latest CMS [11.30.1] and Commerce [13.26.0]

Hi!

I just upgraded to CMS 11.30.1 and Commerce 13.26.0 and now I get this exception when calling ContentRepository.GetReferencesToContent(contentReference, false)

[ArgumentException: An element with the same key already exists in the dictionary.]
System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) +59
System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +675
System.Linq.Enumerable.ToDictionary(IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer) +334
EPiServer.DataAbstraction.ReferenceInformation.CreateReferenceInformation(DataTable data, ILanguageBranchRepository languageBranchRepository, IPermanentLinkMapper permanentLinkMapper) +3124
EPiServer.Core.Internal.DefaultContentProvider.GetReferencesToContentItems(IEnumerable`1 contentLinks) +181
EPiServer.Core.Internal.<>c__DisplayClass45_0.<GetReferencesToContent>b__0(ContentProvider p) +89
EPiServer.Core.ContentProviderMap.Iterate(Action`1 contentProviderHandler) +144
EPiServer.Core.Internal.DefaultContentRepository.GetReferencesToContent(ContentReference contentLink, IEnumerable`1 descendents, Boolean includeDescendants) +205

Any idea why?

Thanks!
/Kristoffer