RESOLVED – I’d missed the “Include Featured Image in Post” setting in Postie/Image. Oops.
Postie is working really well for me except that the featured image is being displayed at the top of the post (correctly) but is also appearing at the bottom of the post body (incorrectly).
I can’t see anything in the post template that would cause this – could it be a Postie issue and if so, how might I fix it??