NET::ERR_CERT_AUTHORITY_INVALID on lots of sites

I have Cloudflare Warp installed, and lots of websites now will not work unless WARP is enabled.
If warp is disabled then they are giving NET::ERR_CERT_AUTHORITY_INVALID
so I assume WARP has caused this issue.

If I check the certificate of said websites, it says they are using Cloudflare SSL.
However if I use a tool such as SSL Checker (sslshopper.com) to check the website, This will show that the site DOES NOT use Cloudflare SSL at all.