Responsive Image - 2x image not being created/used

I'm having issues getting the 2x image to pull in. In the attached on-1x-screen.png the width is 450px which is right. However in on-2x-screen.png the width is also 450px which is not right.

Per the other two attachments I would think the image width should be 900px.

If I use dev tools and try and navigate to the 2x image's path, in my case site.com/sites/default/files/styles/rte_small_2x/public/2020-06/2000x1000-cabin-on-green-grass-field-near-lake-under-white-clouds-3689772.jpg I get a 404.

This is for a Media image being embedded in an RTE.

Here is my theme.breakpoint.yml.

theme.small:
  label: small
  mediaQuery: "(min-width: 0px)"
  weight: 1
  multipliers:
    - 1x
    - 2x
theme.medium:
  label: medium
  mediaQuery: "(min-width: 768px)"
  weight: 2
  multipliers:
    - 1x
    - 2x
theme.large:
  label: large
  mediaQuery: "(min-width: 1024px)"
  weight: 3
  multipliers:
    - 1x
    - 2x

And here is the picture markup that gets generated. Perhaps I'm not configuring things correctly and this is not an actual issue? Let me know if I can provide more information.

<picture>
  <!--[if IE 9]><video style="display: none;"><![endif]-->
  <source srcset="/sites/default/files/styles/rte_small_1x/public/2020-06/2000x1000-cabin-on-green-grass-field-near-lake-under-white-clouds-3689772.jpg?itok=Py1HUx2L 1x, /sites/default/files/styles/rte_small_2x/public/2020-06/2000x1000-cabin-on-green-grass-field-near-lake-under-white-clouds-3689772.jpg?itok=of1O5uTj 2x" media="(min-width: 1024px)" type="image/jpeg">
  <source srcset="/sites/default/files/styles/rte_small_1x_tablet/public/2020-06/2000x1000-cabin-on-green-grass-field-near-lake-under-white-clouds-3689772.jpg?itok=791cmchA 1x, /sites/default/files/styles/rte_small_2x_tablet/public/2020-06/2000x1000-cabin-on-green-grass-field-near-lake-under-white-clouds-3689772.jpg?itok=WNjXGok5 2x" media="(min-width: 768px)" type="image/jpeg">
  <!--[if IE 9]></video><![endif]-->
  <img src="/sites/default/files/styles/large/public/2020-06/2000x1000-cabin-on-green-grass-field-near-lake-under-white-clouds-3689772.jpg?itok=NO-4E6cA" alt="a" typeof="foaf:Image">
</picture>