In a secure connection using HTTPS, clients verify servers' identities by validating their TLS certificates. However, this process can fail due to incomplete certificate chains, where servers have valid certificates but lack required intermediary certificates, making it difficult for clients to establish trust. This issue affects not only webhooks but all TLS servers and web servers, leading to failed connections and other security issues. To resolve the issue, servers should return the full certificate chain in their TLS response, excluding the root certificate, and verify that the configuration is fixed using tools like Qualys SSL Test.