What am I doing wrong? Moving images from one WP installation to another

Hi everyone

My site – https://philipus.com – has a subdomain called https://articles.philipus.com on which I have only a few pages. I wish to move these to the main site. I used the Tools -Export function for the pages on “articles” and then the Tools – Import function on the main site. This resulted in the pages ending up on the main site. BUT the images linked to in those pages, all of which are hosted on “articles”, were not exported/imported. Ideally, I would want to have them hosted on the main site because I wish to close “articles”.

I also tried copying over the image files using FTP (Cyberduck) from “articles” to the main site and changing the links in the pages on the main site to the images’ location in that site’s hierarchy but that does not work, for some reason.

I’d very much appreciate your help.

Kind regards
Philip