AWS API Gateway Caching by Query Parameter not working

Question

This is question is slightly different than this question, but related. I have AWS API gateway setup with a single GET method, which has 1 query parameter search. This GET call returns a list of words based on the search string. I have turned on caching by this query parameter, but get the same results, no matter the query parameter. When I turn caching off, it works as expected.

1. First request search=a* => words that start with a are returned, as expected
2. Second request search=b* => words that start with a are returned, but I expect words that start with b.

Why aren't my requests being cached by the query parameter?

API Settings:

Method Query Parameter:

Answer 1

It might help if I actually deployed the API after making the changes.