Hi,
I have an update that it is not just mobile. I had omitted to look at my site from desktop when logged out of WordPress.
I can confirm today that on both mobile and desktop (including incognito and logged out of WP) that the three articles I added today have not refreshed the front page, nor has the 'overview page' been updated.
When I view via WP logged in I see all the changes.
Therefore I surmise that the cache is not being cleared as it should.
For the sake and need of traffic I am going to clear the caches for these pages manually now, but I'd appreciate this being looked into as from what I can tell this has only recently started to happen.