Get dial tcp connect: connection refused

Hi, i setup a kubernetes from scratch on VM. After setup everything, i get below errors as shown in the screenshots. Is there anything i miss out?

Cluster information:

Kubernetes version: v1.18.6
Cloud being used: on-premise setup
Installation method:on-premise setup
Host OS: Ubuntu 18.04
CNI and version: Flannel v1.7
CRI and version: 19.03.12

I have the same problems. it looks like a known bug.