Repositories in UOW do not work

I have configured a Unit of Work (UOW) class that contains a variety of GlobalCacheRepositories pretty much exactly as per the TempHire reference application. 
I have a GlobalChache class that has been loaded with the data these repositories reference as well (again as per TempHire). 

However when I try to obtain data (in the ViewModel) from the UOW repositories 0 records are always returned. As a test I have passed the Global Cache to the function and queries that directly, and records are returned.

e.g.

                 // this will return 0 records
                var issuetreatments = await UnitOfWork.IssueTreatments.AllAsync(q => q.OrderBy(s => s.Name));

                // this will return 5 records (the correct amount)
                var issuetreatments2 = cache.Get<IssueTreatement>();

Does anyone have any pointers as to why this would be occuring?

Thanks
Mark