Can you supply your npvr.db3 file? I'm guessing there is something specific about your channel names or the name of a show or something similar, which the apple tv app isn't happy with.
With your database I should be able to reproduce the issue here.
Thanks for all your help. After tinkering with the setup, I think I have it working now. I think it was an issue with the Channel Mapping. Numbers were not matching actual channels.