Proxy request to shopify provider dies mid-operation → 502 (self-hosted 0.70.9 & 0.71.0)

On self-hosted nango-server hosted-0.70.9 (and 0.71.0), every GET /proxy/... for a shopify (OAuth) connection returns a 502 (the operation logs state: running and never completes — no error logged, endedAt stays null). Same for shop.json (no scope needed). - The connection is healthy: OAUTH2 creds, read_products scope, connection_config.subdomain set; management API returns it fine. - From inside the Nango pod, node -e 'fetch("https://<shop>.myshopify.com/admin/api/2026-01/shop.json")' returns a clean 401 (and 200 with the stored X-Shopify-Access-Token) — so the pod reaches Shopify's Admin API; egress is fine. - Every other provider proxies at 200 on the same instance, including other connect-session/end-user connections. Only the shopify provider 502s. - Provider config is stock: proxy.base_url = https://${connectionConfig.subdomain}.myshopify.com, header x-shopify-access-token: ${accessToken}. Sending an explicit base-url-override doesn't help. Looks like the proxy handler dies mid-request specifically for the shopify provider template. Happy to provide debug logs.