Cluster nodes are "Active" but cluster is in "error" state


I’m new to Rancher, and I couldn’t create a successful cluster yet. Here’s the current setup:
1- OS: CentOS 7.9
2- Kernel: Linux 3.10.0-1160.6.1.el7.x86_64
3- Node cound: four nodes (including Rancher installation node)
4- Deployment model: Docker Installation (just for training purposes).
5- Rancher version: 2.5.latest
6- Docker CE 19.03.14
7 - Docker refuses to run without FirewallD started,so, the following ports are allowed on all nodes:

  • 6443/tcp
    - 2379-2380/tcp
    - 10250/tcp
    - 10251/tcp
    - 10252/tcp
    - 10255/tcp
    - 30000-32767/tcp
    - 8472/udp
    - 4789/udp
    - 9099/tcp
    - 9796/tcp
    - 10254/tcp
    - 5473/tcp
    - 179/tcp
    - 443/tcp
    - 80/tcp
    - 22/tcp
    - 8285/udp

I created a new cluster (with all set to default, Canal, and cluster type “none”, and all of the nodes are in active state, one master, and two workers, and then I made all masters, but the cluster is still in “Error” state with the following error:

All hosts have the same “hosts” file, and they all can ping each other with host name.

" This cluster is currently Error ; areas that interact directly with it will not be available until the API is ready. Cluster health check failed: cluster agent is not ready"

Thank you,