Latest post not updated evenly across devices (PC, mobile and tablet)

I have a daily post on my website. In the past, as soon as I post, I will be able to see the latest post on my PC, Mac, mobile phone and tablet instantly. Recently, after I post, the pages on my different devices (PC, Mac, mobile and tablet) do not show the latest post. I know my post was successful as I have set up a sharing on Facebook and the lastest post is already updated on FB. I would be able to click on the FB link and go to the latest post. However, when I go directly to my url on my devices, the post I see can be an old post, of two days or a day old. When I try to refresh, nothing happens. On the different devices, I see different posts too.

The latest post might get refreshed anytime between 2 – 24 hours later.

I have WP Super Cache enabled. So my cache should be cleared. I have also purged all history and cookies on my devices but nothing works.

How can I solve this issue?

Please help this non-technically inclined person who only knows how to write and post. My website is ParkSihooSsi.com