I took your advice and installed the Github Updater plugin and then started from scratch removing your theme from my site initially. I then re-installed the master iwtwentyfifteen theme from Github via the plugin interface and also created a child theme directory in my FTP client, Cyberduck, which I titled ‘iwtwentyfifteen-child’. I then activated the child theme in WordPress – its style.css simply imports your master style.css – and it recognised the footer images you had added in your source img folder, etc. so I’m hoping all is okay with its title including ‘-child‘.
Unfortunately, doing this didn’t resolve the display issues on either the pages or the single posts at the canonical URLs. I made some very minor amendments to the footer.php but didn’t make any direct changes to content, single, or index.php files. I use the Settings > Insert Headers and Footers area on WordPress to add a few rel links and endpoints (authorization, token, microsub server). I removed each of these and re-added them but they didn’t appear to make any difference. I also removed and re-added each of the widgets I was displaying, but no joy with that either.
However – dealing with the page issue firstly – I inspected my website source and noticed that the ‘hentry’ class seems to be absent beneath the
article tag on my pages. It appears to be present on your site pages under the
article tag. Once I add hentry as a class to the article tag on each of my pages in the inspector, they then appear as yours do, which is brilliant. I’m not confident about where I should get this working in the theme code though, would you know the best place(s) to remedy this within my code so that all pages will use the hentry class?
I thought if I created a new test page that the hentry class might be included in that (trying to rule out the possibility that it was only older legacy pages on my site that wouldn’t include the hentry class, for whatever reason), but unfortunately not.
I haven’t yet figured out much new info. with the quirky display issue of the canonical single posts URLs. When I inspect the source of any canonical single post there does seem to be a lot of extra bloat at the top and left hand side of the page around the sidebar.