Deploy Ranche 2.6 slow when using HA ( 3 node ) slow

Hi everyone …
I new user in rancher.
I have plan migration my AWS ECS will be using Rancher .
I following documentation in ranche website .
I have 2 or 3 instance in aws ( using t3a.large and t3a.medium ) .

  1. Install k8s using rke with 3 instance ( 1 t3a.large , 2 t3a.medium as etcd , controlplane and worker ) . Instaled k8s is working fine event get notify ingres nginx and admin but i can ignore it.
    2.Install rancher ( cert manager 1.6.0 and latest rancher using helm )
    3.Then i using AWS ALB as endpoint which target port 80 to instance k8s
  2. The respond dashboard very slow and take a time to install rancher , event i must helm upgrade to push instalation since always time out .
  3. The problem was gone if i only use 1 instance ( t3a.large)
    So any one here have good guide to install rancher in k8s using 3 node ?
    since when i use 1 node to install rancher will be problem monitoring will be take cpu resource also i need feature longhorn for rancher .
    Many thanks for any commnet and help and guideline