Why HubSpot CRM Resets Connections on Sequoia
HubSpot CRM is hosted on HubSpot’s own cloud infrastructure with Cloudflare as the CDN layer. The platform uses TLS 1.3 with ECH for all authenticated sessions. When users access HubSpot CRM from macOS Safari on networks with SSL inspection, the ISP gateway resets the ECH-enabled ClientHello, causing the TLS handshake to fail.
HubSpot’s TLS configuration supports TLS 1.2 fallback, but Cloudflare’s edge policy requires ECH for TLS 1.3 and only offers TLS 1.2 fallback when explicitly signaled by the client. ISP gateways that strip the TLS 1.2 signal cause Cloudflare to assume TLS 1.3-only support, which fails.
Browser Integrity Sync on HubSpot’s Infrastructure
HubSpot CRM uses browser integrity sync to prevent unauthorized access to CRM data, marketing pipelines, and customer records. When the TLS handshake is interrupted, the integrity sync fails, and HubSpot’s security layer blocks the user’s session, requiring re-authentication.
Fixing HubSpot CRM Connection Resets
Using Chrome with QUIC Disabled
HubSpot’s Cloudflare configuration supports HTTP/3 (QUIC), which can be blocked by ISP gateways. Download Chrome → Settings → Advanced → System → disable Use QUIC protocol. Access HubSpot CRM in Chrome — with QUIC disabled, Chrome uses HTTP/2 over TCP, which ISP gateways handle reliably.
Switching to Firefox with TLS 1.2 Maximum
Download Firefox → navigate to about:config → security.tls.version.max → set to 3. Access HubSpot CRM in Firefox — TLS 1.2 does not require ECH, allowing the handshake to complete through ISP gateways that block ECH.
Disabling Corporate Proxy for HubSpot Domains
Configure your network proxy to bypass HubSpot domains. In macOS, navigate to System Settings → Network → Wi-Fi → Details → Proxy. Add *.hubspot.com, *.hs-analytics.net to the bypass list.
Call to Action
Use the webs.ninja network lab to verify connectivity to HubSpot CRM endpoints. The diagnostic identifies whether the reset is caused by your ISP’s gateway, a Cloudflare edge node failure, or HubSpot’s platform infrastructure, directing the fix to the correct layer.