Imbalance lua ingress-nginx

Hello to all the ranchers :),
I have interesting problem with imbalance inside the k8s cluster with 3 nodes.
this is number of API request per second 24-hour statistics
NODE1: |min:1.80|max:6.73|avg:2.38|
NODE2: |min:0|max:28.73|avg:0.58|
NODE3: |min:1.067|max:4.133|avg:1.578|

all Nodes are the same.
should the value be approximate on each node ?
There is any documentation how Load Balancig works in K8s claster on ingress-nginx controler ?

I don’t get it.