Following a scheduled TLS certificate renewal, a subset of Netdata agents failed to reconnect to Netdata Cloud. The issue stems from outdated CA (Certificate Authority) trust stores on certain legacy Linux distributions, like: • CentOS 7 / RHEL 7 • Amazon Linux 2 • Debian 9 (Jessie) • Ubuntu 16.04 LTS • Oracle Linux 7 A quick way to test for this: curl -v https://app.netdata.cloud If the output shows an error indicating the certificate has expired, the system needs an updated CA bundle.