Fresh install, can't generate schema documentation for new content types

[mminklet]

Fresh install with updated latest versions through composer, no dummy content. I can't create a basic content type and have anything at all show up in admin/api, I get this hanging page and this 500 error in the response. Content type is simply a title and body field.

Call to a member function getEntityTypeId() on null in <em class="placeholder">Drupal\openapi\Plugin\openapi\OpenApiGenerator\JsonApiGenerator-&gt;getPaths()</em> (line <em class="placeholder">157</em> of <em class="placeholder">modules/contrib/openapi/src/Plugin/openapi/OpenApiGenerator/JsonApiGenerator.php</em>). <pre class="backtrace">Drupal\openapi\Plugin\openapi\OpenApiGenerator\JsonApiGenerator-&gt;getPaths() (Line: 213)
Drupal\openapi\Plugin\openapi\OpenApiGeneratorBase-&gt;getSpecification() (Line: 39)
Drupal\openapi\Controller\ApiSpecificationController-&gt;getSpecification(Object, Object)
call_user_func_array(Array, Array) (Line: 123)