Running the below commands...

k3d cluster create challenge2 --agents 3 -p "8080:80@loadbalancer

kubectl create deployment k3d-challenge2-agent-0 --image nginx:latest

... creates pods on the master node/control plane...:

default       k3d-challenge2-agent-0-7894df65f8-c2j6v   0/1    ContainerCreating   0        
  4s     <none>     k3d-challenge2-server-0   <none>           <none> 

... as indicated by the presence of k3d-challenge2-server-0.

Does anyone know why this happens and how to avoid it?

Thanks in advance