https://git.drupalcode.org/project/jsonapi_include/-/merge_requests/28 is resolving this issue for me for now but is more of a work around for sure.
The issue is the resources are cached so on the second pass we're never hitting the following:
https://git.drupalcode.org/project/jsonapi_extras/-/blob/8.x-3.x/modules...
which sets the default includes param to the request
$request->query->set('include', implode(',', $includes));
Either jsonapi_defaults needs to ensure this is set even when loading the resource response from cache or jsonapi_include needs to think about caching too - if we cache the generated output from `parseJsonContent` with the same cache tags / context as the resource then we'll only be processing when uncached and therefore have the include param available.
breidert → credited reecemarsland → .
Our use case is indexing PDF files attached to content and we need the PDF content to be searchable.
Thanks loze - patch for MR in #7 is working perfectly.