[Django]-Process_template_response doesn't get called in Django

From the documentation (emphasis mine):

process_template_response() is called just after the view has finished executing, if the response instance has a render() method, indicating that it is a TemplateResponse or equivalent.

You state that you’re using django.http.shortcuts.render, whose documentation reads:

Combines a given template with a given context dictionary and returns an HttpResponse object with that rendered text.

Django does not provide a shortcut function which returns a TemplateResponse because the constructor of TemplateResponse offers the same level of convenience as render().

Thus render returns a HttpResponse, not a TemplateResponse, and as noted above, process_template_response is only called for TemplateResponses.

You either need to change your view to return TemplateResponse, instead of using the render shortcut, or perform your logic elsewhere. I think your logic could be implemented in a context processor instead of middleware.