SSL issue please help!

Hey team, I am having a very strange issue where my laptop isn't accepting the SSL certificate of a website. Not only that but whenever I login into WordPress, I am still being served an old version of the website, even though it's been updated by colleagues.

I know it;s not SEO related specifically, but it's hard to perform SEO for a website that you cannot see LOL

I have already done the following:

• Cleared cache and history and multiple browsers.
• Flushed DNS cache
• Try a different internet connection (including hotspot)
• Contacted the hosting service to diagnose

The rest of my team can see the website just fine and are not getting the SSL error.

Would you know what can cause such an error?

Thanks!