Hello,
Sorry but if it's working standalone, we have tested with the change in your DOCX explained on our previous update and the output is correct, then there must be something wrong about how it's being used/integrated with the CMS that we can't guess.
The namespaces package is fully tested with CMS such as WordPress and Drupal and frameworks (Symfony, Laravel, Yii, CakePHP...). Type3 should work fine too, and we are aware that other users are using phpdocx namespaces with Type3 without issues.
We recommend you try using the included samples in your Controller, maybe it can't read the images due to some missing rw access.
Regards