[Solved]-'Suspicious Operation: Attempted access to "" denied' while loading static files

Sorted! As expected it was something annoyingly simple but perhaps this will help anyone else who hits the same wall.

This:

<link rel="stylesheet" type="text/css" href="{% static '/css/reset.css' %}">

Needed to be this:

<link rel="stylesheet" type="text/css" href="{% static 'css/reset.css' %}">

I.e. no leading slash in the href. Worked fine using local static files storage but broke the S3 link.