write tcp [2605:4c40:33:6be3:0:94f0:6c50:1]:46096->[2a09:8280:1:f132:9b03:c39f:b404:f5d2]:443: write: broken pipe
How are you deploying to fly? locally with flyctl or from a remote CI/CD server using flyctl? Can you share your command you are using and maybe your fly.toml?
Are you using the latest flyctl version?
You could try to also restart your local fly agent fly agent restart
Hope my questions may help you find a fix