I say unexpected, but I can understand how it came about so it can be expected, but just undocumented.
With lambda, I have a type that has a field that uses the lambda directive to return a concatenated string of other fields. That mostly works well. However when I add a cascade directive on a query, I would expect to get some results but it returns no results. The cascade seems to be looking for the field pre lambda resolve which of course it does not exist.
How to produce: Create a type with a simple lambda field that equates another string field or even the id. And then query those two fields and add the cascade directive. Now the results will be null.