Try z.mkv and z.Engilish.ac3. Also thus feature depends on splitter and filters you're using. Should work with AVSplitter and MPC Splitter. Right, @Sebastiii?
It was working before but with the ton of the answer @andreyua, it doesn't give the punch to try to look on this.
First log is missing and it could be nice to upload a sample for testing to compare with future log