I have a lambda function with an authorizer sitting within an API gateway.
I notice that when I call the lambda function, on the first request the authorizer is invoked as expected, authorization passes, IAM role is assumed and grants access to the lambda function.
However, on subsequent requests, the authorizer is not invoked.
I assume this is due to authorization caching.
However, in the AWS console, in API gateway > Authorizers the authorizer has the following configuration:
Authorizer ID: iiii2l
Lambda Function
 foo-authorizerV1-dev-authorizer (eu-west-1)
Lambda Invoke Role
 arn:aws:iam::0000000:role/foo-authorizerV1-dev-AuthorizerRole-AAAAAAA
Lambda Event Payload
 Request
Identity Sources
 deviceID (header)
Authorization Caching
 Authorization not cached 
I would have thought Authorization Caching being set to Authorization not cached  would mean that the authorizer would be invoked on every request.
Am I missing something here?