There is currently a CVE which affects Traefik, it's not yet published (work in progress).
The 2.11.1 release was packed with this PR, introducing respondingTimeouts.lingeringTimeout to mitigate the vulnerability. This implementation was carefully chosen after many discussions to avoid being breaking at all costs. Sadly, we haven't anticipated all use cases, and many issues have been opened by the community since the release.
We made the decision to rollback the lingeringTimeout PR, and to provide a simpler fix by tomorrow. We haven't been able to find a fix for this vulnerability that is not breaking at some point. However, the new fix we are going to provide is simpler to understand and configure to fit your needs.
Started noticing websocket errors on multiple docker containers. These errors were causing multiple web pages reload after about ~5 seconds with a HTTP status 101 response. Unraid does not show the 2.11.2 version available yet so downgrading to 2.11.0 showed success. Manually setting the container to traefik:2.11.0 and traefik:2.11.2 resolved the issue.
Just posting in case someone runs into the same issue.