Jan 11 13:02:48 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2281]: Flag --tls-private-key-file has been deprecated, This parameter should be set via the config file specified by the Kubelet's --config flag. See <https://kubernetes.io/docs/tasks/administer-cluster/kubelet-config-file/> for more information.
Jan 11 13:02:51 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:02:51+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"
Jan 11 13:02:52 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:02:52+01:00" level=info msg="Waiting to retrieve kube-proxy configuration; server is not ready: <https://127.0.0.1:9345/v1-rke2/readyz>: 500 Internal Server Error"
Jan 11 13:02:56 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:02:56+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"
Jan 11 13:02:58 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:02:58+01:00" level=info msg="Waiting to retrieve kube-proxy configuration; server is not ready: <https://127.0.0.1:9345/v1-rke2/readyz>: 500 Internal Server Error"
Jan 11 13:03:01 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:01+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"
Jan 11 13:03:03 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:03+01:00" level=info msg="Waiting to retrieve kube-proxy configuration; server is not ready: <https://127.0.0.1:9345/v1-rke2/readyz>: 500 Internal Server Error"
Jan 11 13:03:06 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:06+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"
Jan 11 13:03:06 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:06+01:00" level=info msg="Container for etcd not found (no matching container found), retrying"
Jan 11 13:03:08 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:08+01:00" level=info msg="Waiting to retrieve kube-proxy configuration; server is not ready: <https://127.0.0.1:9345/v1-rke2/readyz>: 500 Internal Server Error"
Jan 11 13:03:11 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:11+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"
Jan 11 13:03:13 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:13+01:00" level=info msg="Waiting to retrieve kube-proxy configuration; server is not ready: <https://127.0.0.1:9345/v1-rke2/readyz>: 500 Internal Server Error"
Jan 11 13:03:16 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: {"level":"warn","ts":"2023-01-11T13:03:16.760+0100","logger":"etcd-client","caller":"v3@v3.5.4-k3s1/retry_interceptor.go:62","msg":"retrying of unary invoker failed","target":"<etcd-endpoints://0xc0005ff340/127.0.0.1:2379>","attempt":0,"error":">
Jan 11 13:03:16 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:16+01:00" level=info msg="Failed to test data store connection: context deadline exceeded"
Jan 11 13:03:16 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:16+01:00" level=info msg="Waiting for etcd server to become available"
Jan 11 13:03:16 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:16+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"
Jan 11 13:03:16 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:16+01:00" level=info msg="Waiting for API server to become available"
Jan 11 13:03:18 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: {"level":"warn","ts":"2023-01-11T13:03:18.136+0100","logger":"etcd-client","caller":"v3@v3.5.4-k3s1/retry_interceptor.go:62","msg":"retrying of unary invoker failed","target":"<etcd-endpoints://0xc0005ff340/127.0.0.1:2379>","attempt":0,"error":">
Jan 11 13:03:18 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:18+01:00" level=error msg="Failed to check local etcd status for learner management: context deadline exceeded"
Jan 11 13:03:18 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:18+01:00" level=info msg="Waiting to retrieve kube-proxy configuration; server is not ready: <https://127.0.0.1:9345/v1-rke2/readyz>: 500 Internal Server Error"
Jan 11 13:03:21 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:21+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"
Jan 11 13:03:23 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:23+01:00" level=info msg="Waiting to retrieve kube-proxy configuration; server is not ready: <https://127.0.0.1:9345/v1-rke2/readyz>: 500 Internal Server Error"
Jan 11 13:03:26 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:26+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"
Jan 11 13:03:26 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:26+01:00" level=info msg="Container for etcd not found (no matching container found), retrying"
Jan 11 13:03:28 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:28+01:00" level=info msg="Waiting to retrieve kube-proxy configuration; server is not ready: <https://127.0.0.1:9345/v1-rke2/readyz>: 500 Internal Server Error"
Jan 11 13:03:31 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:31+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"
Jan 11 13:03:33 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: {"level":"warn","ts":"2023-01-11T13:03:33.136+0100","logger":"etcd-client","caller":"v3@v3.5.4-k3s1/retry_interceptor.go:62","msg":"retrying of unary invoker failed","target":"<etcd-endpoints://0xc0005ff340/127.0.0.1:2379>","attempt":0,"error":">
Jan 11 13:03:33 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:33+01:00" level=error msg="Failed to check local etcd status for learner management: context deadline exceeded"
Jan 11 13:03:33 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:33+01:00" level=info msg="Waiting to retrieve kube-proxy configuration; server is not ready: <https://127.0.0.1:9345/v1-rke2/readyz>: 500 Internal Server Error"
Jan 11 13:03:36 <http://srvl034a.ac.aixigo.de|srvl034a.ac.aixigo.de> rke2[2193]: time="2023-01-11T13:03:36+01:00" level=info msg="Tunnel server egress proxy waiting for runtime core to become available"

Any helpful hint is highly appreciated.

check the logs under /var/log/pods for the kube-system_etcd pods, see why its failing to start