Hi there, hope someone can help

getting error NET::ERR_CERT_AUTHORITY_INVALID using my PC/network. My PC is connected to router via ethernet, so not on a wifi

Happening only with certain web pages like the final fantasy 14 wiki page. I know the page is working as works on my mobile phone when I turn off the wifi

Things I have tried:

Incognito window

Using another internet browser

Turning off fire wall temporarily

Emptying cache and browser history

re-loading page several times

I use norton 360, done a scan

I did at one point turn on the VPN with norton and it then worked, but I have to have my VPN off for various reasons

Anyone any ideas?

I will be honest, most stuff on my PC I can figure out and fix myself through Dr google, but this has baffled me. I don’t understand what the SSL certificate function is, as I understand it, it makes a website reputable so you can trust it, but it’s doing the exact opposite. I looked online and saw adverts about buying a certificate, which seems crazy, not sure why that was suggested. It doesn’t seem to be my fire wall (tried turning that off) I emptied all the history/cache, so what is it that is telling my PC to block this website?