Webp images are not generated

Problem/Motivation

I have webp support enabled on my server.
I have webp enabled
I have responsive image styles working

When I visit a page with an image using a responsive style I get no webp images.
There are no errors in the logs.
There are no apache errors.
I'm not sure next steps to debug.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes