I'm running Traefik 2.10.6 in my K3S cluster and I have - among other services - Jellyfin reverse proxied by Traefik. Every so often if I try to access Jellyfin in Firefox I get the error
SSL_ERROR_NO_CYPHER_OVERLAP, but only in Firefox and only with this one service and it seems to resolve itself after maybe half an hour or so.
For example here's the Ingress object for Sonarr: https://github.com/UntouchedWagons/K3S-Cluster-Setup/blob/main/production/servarr/sonarr/service.yaml#L155-L180
And here's the Ingress object for Jellyfin: https://github.com/UntouchedWagons/K3S-Cluster-Setup/blob/main/production/default/jellyfin/service.yaml#L114-L139
As far as I can tell, aside from stuff like what Service and port to use, everything is effectively identical.
You can see how I install Traefik on my cluster here: https://github.com/UntouchedWagons/K3S-Cluster-Setup/blob/main/production/readme.md#traefik
I'm using Firefox 122.0 on Windows 10 Pro.