One of my client's sites stopped working in Chrome 117 (ERR_SSL_VERSION_OR_CIPHER_MISMATCH) due to either a bug in Cloudflare or in Chrome due to this TLS 1.3 ECH feature. I spent many hours troubleshooting a very basic/default setup with Cloudflare in front of our website and with Chrome 117, and finally was able to fix the issue by disabling TLS 1.3 (for now) in Cloudflare since they currently have a beta of Encrypted ClientHello (ECH) enabled in all Free zones. Hoping this comment might help any other devops / network administrators out there with this problem. I've submitted a bug report to both the Chrome team and to Cloudflare.