## The problem

Issue langgenius/dify#39154 (closed, 60 comments): ### Self Checks - [x] I have read the [Contributing Guide](https://github.com/langgenius/dify/blob/main/CONTRIBUTING.md) and [Language Policy](https://github.com/langgenius/dify/issues/1542). - [x] This is only for bug report, if you would like to ask a question, please head to [Discussions](https://github.com/langgenius/dify/discussions/categories/general). - [x] I have searched for existing issues [search for existing issues](https://github.com/langgenius/dify/issues), including closed ones. - [x] I confirm that I am using English to submit this report, otherwise it will be closed. - [x] 【中文

## The verified fix

Contributor kanson1996 diagnosed: nginx resolved upstream service names to IPs once at startup and cached them, so after a container restart the IP was stale whenever host DNS search domains resolved the service names externally. Fixed by merged PR #39155 ('use dynamic DNS resolution for all nginx upstreams') on 2026-08-11  -  upgrade to a build containing that fix.