You have registered your dns-zone as uswest2.dev.devops.com and you are referring in command to name as dev.devops.com.

If you will check this docs, especially Configure DNS section, you will find that:

In this scenario you want to contain all kubernetes records under a subdomain of a domain you host in Route53. This requires creating a second hosted zone in route53, and then setting up route delegation to the new zone.

In this example you own example.com and your records for Kubernetes would look like etcd-us-east-1c.internal.clustername.subdomain.example.com

You will find that based on this doc example: etcd-us-east-1c.internal.clustername.subdomain.example.com Your dev.devops.com is domain and uswest2.dev.devops.com is your subdomain.

In Route 53 docs you will be able find example where subdomain for example.org in this case was set as kopsclustertest

export ID=$(uuidgen)
echo $ID
ae852c68-78b3-41af-85ee-997fc470fd1c

aws route53 \
create-hosted-zone \
--output=json \
--name kopsclustertest.example.org \
--caller-reference $ID | \
jq .DelegationSet.NameServers

[
  "ns-1383.awsdns-44.org",
  "ns-829.awsdns-39.net",
  "ns-346.awsdns-43.com",
  "ns-1973.awsdns-54.co.uk"
]

At this moment: subdomain: kopsclustertest domain: example.org

A few chapters below you will find KOPS CLUSTER CREATION section.

kops create cluster \
--cloud=aws \
--master-zones=us-east-1a,us-east-1b,us-east-1c \
--zones=us-east-1a,us-east-1b,us-east-1c \
--node-count=2 \
--node-size=t2.micro \
--master-size=t2.micro \
${NAME}

with information that

The environment variable ${NAME} was previously exported with our cluster name: mycluster01.kopsclustertest.example.org.

It means that before subdomain.domain you need to specify your cluster name.

In short, in flag --name you must specify: <your_cluster_name>.subdomain.domain

Please try:

kops create cluster --cloud=aws --zones=us-west-2b --name=my-cluster.uswest2.dev.devops.com --dns-zone=uswest2.dev.devops.com --dns private