I have set up my website on my custom domain with https on your Sites, and everything was working fine, but recently, the ssl stopped working, and I keep getting (Site not secure) when connecting to https.
I have nothing funny set up, and followed your instruction through the Publish process.
the site is www.zerorisk.one
It seems to be the same with my other two sites as well.
Websites prove their identity via certificates. Firefox does not trust this site because it uses a certificate that is not valid for www.zerorisk.one. The certificate is only valid for the following names: *.bss.design, bss.design
Error code: SSL_ERROR_BAD_CERT_DOMAIN
Sorry for replying so late. You've likely turned off proxy-ing your requests in cloudflare (the orange cloud in the control panel). The result is that web browsers attempt to connect to our server requesting your domain. But we don't and can't issue an SSL certificate for your site, so https connections fail.
When you switch on proxying in cloudflare, they will handle the certificate issuance on your domain and https will work.