I added some new objects and changed the HDR rotation in an existing blend file, but whenever I hit F12 or Ctrl+F12 I only seem to get a render output of the scene before my recent additions and changes.
As the attached image shows, the added items are outlined/selected and visible in all viewport versions including render view and the new HDR position shows correctly.
Some objects are newly created within this file, some are duplicates (not instances) of objects in this file, and others are copied/pasted from other blend files. They are all scattered within several existing collections and render layers that have previously rendered correctly.
All the visibility and render options are correctly set in the outliner.
Composite node is set up correctly.
I've saved/closed/reopened blender and the blend file.
I've gone through the checklist of all likely causes for objects not showing Why does my object not show up?
Although I am not a newbie to blender, I have just switched from 2.79 to 2.83 so I'm not sure if there is something new I haven't learnt yet but it seems like this is rendering a cached version of the scene or something and not what is currently there.