Here is the rancher agent pod logs:

CATTLE_INTERNAL_ADDRESS= CATTLE_IS_RKE=false CATTLE_K8S_MANAGED=true CATTLE_NODE_NAME=cattle-cluster-agent-86d667c95f-ltqp9 CATTLE_SERVER=<https://35.225.85.114> CATTLE_SERVER_VERSION=v2.6.8
INFO: Using resolv.conf: search cattle-system.svc.cluster.local svc.cluster.local cluster.local c.rene-v-sandbox.internal google.internal nameserver 10.0.0.10 options ndots:5
ERROR: <https://35.225.85.114/ping> is not accessible (Failed to connect to 35.225.85.114 port 443: Connection timed out)

Hi, @victorious-river-3598 Dumb question... I saw that your Rancher environment is visible, so port 443 is opened and working, but have you configured Cloud NAT on the GKE cluster so Pods can reach the Internet?