I used the patch and still was not able to see the headers properly set, I th...

I used the patch and still was not able to see the headers properly set, I then checked the module ajax_cached_get but no luck, I than checked the differences in use of CacheableResponseTrait and it seemed that all the conditions were failing as response object was not instance of CacheableResponseInterface.

Updated the patch, now ViewAjaxResponse implements CacheableResponseInterface and CacheableResponseTrait was already used. Confirmed for my case the headers are properly set now.

Patch is only for 8.3.x as of now and once I confirm it on Acquia cloud I will work on 8.4.x