I’ve had cause to play around with the images in a blog post but I’m not sure this is working. Could be my understanding though!
Under Customizing > Blog / Post image, do the various options work on the featured image?
I’ve tried adding an image to the Page Header, top of the post content and using a featured image but can’t get the options to work (Post Image, Post Image Position, Post Image Alignment etc).
I think I’ve been a bit dumb. I’ve just figured that these settings affect the actual blog listings, not the image in the individual single blog post itself!
I now think it’s working as expected. Sorry for wasting your time!