We do have Ken Burns on our list. We did notice someone named Ken ... and another person named ... Burns in the cast list.
Some more snooping and comparing showed that we had erroneously entered Ken Burns as a keyword match instead of Burns, Ken as Director and that is why. Interesting that in the almost 2 years we've had the Tivo and I think Ken Burns was on the list from pretty early on we have no such instances of this match.
Yes, of course, we never read the manual.