Diagnosing ERR_CONNECTION_RESET on Payment Gateway Pages
When Safari returns ERR_CONNECTION_RESET on cross-border payment pages (PayPal, Stripe, Adyen), the issue is almost always a TCP-level connection termination initiated by an upstream device — typically the ISP gateway or a corporate proxy performing SSL inspection. The connection is not timing out; it is being actively reset by a middlebox that cannot parse the TLS 1.3 Encrypted Client Hello payload.
Cross-border payment gateways use TLS 1.3 with ECH to protect the confidentiality of the connection, including the payment page URL and any session cookies. When macOS Sequoia’s Safari initiates the handshake, the ECH extension is sent in the ClientHello. Legacy gateway appliances that perform SSL inspection do not support ECH decryption and respond with a TCP RST, causing Safari to display ERR_CONNECTION_RESET.
Why macOS Sequoia’s TLS Stack Is More Strict Than Previous Versions
macOS Sequoia enforces TLS 1.3 as the minimum protocol version for all SecureTransport API calls. Previous macOS versions allowed fallback to TLS 1.2, which does not require ECH. When a legacy middlebox resets a TLS 1.3 connection, Safari cannot fall back to TLS 1.2 because the server advertises only TLS 1.3 support, resulting in the immediate reset error.
Fixing ERR_CONNECTION_RESET in Safari
Disabling VPN and SSL Inspection Locally
If you use a corporate network with SSL inspection, the gateway appliance is almost certainly the culprit. Try connecting to the payment page via your personal mobile hotspot (not the corporate Wi-Fi). If the page loads successfully, the corporate proxy is resetting the TLS 1.3 handshake. In this scenario, use a personal VPN that encrypts all traffic before it reaches the corporate proxy — the encrypted payload cannot be inspected and is passed through without reset.
Modifying Safari’s TLS Version Handling
There is no user-accessible toggle in Safari to force TLS 1.2 fallback. However, you can work around the issue by using a different browser (Chrome or Firefox) that has its own TLS stack and may negotiate TLS 1.2 with the payment gateway if the server supports it. Download Chrome from the official Google website and test the payment page in Chrome — if it loads, the issue is Safari’s TLS 1.3 enforcement specifically.
Clearing macOS Keychain TLS Certificates
Corrupted TLS certificates in the macOS Keychain can cause Safari to fail TLS handshakes at the certificate validation stage, manifesting as a connection reset. Open Keychain Access → System → All Items, search for the payment gateway’s domain, and delete any certificates associated with it. Restart Safari — the browser will request a fresh certificate from the gateway’s server, bypassing the corrupted entry.
Call to Action
Before reinstalling Safari or adjusting network settings, use the webs.ninja network lab to run a TLS handshake diagnostic that identifies exactly where the connection is being reset. If the diagnostic confirms the reset is coming from your local network infrastructure (corporate proxy or ISP gateway), the fix is VPN-based. If the diagnostic shows the reset is coming from a CloudFront edge node, use the AWS CloudFront routing metrics panel to identify an alternative edge node and bypass the degraded path.