Deploying changes to individual Lambdas using Serverless Framework

I have a serverless project that deploys 2 Lambdas in the same stack:

service: example-apis2

provider:
  name: aws
  memorySize: 512
  region: us-west-1
  apiGateway:
    restApiId: ${env:APIGWID} #  API Gateway to add this api to
    restApiRootResourceId: ${env:RESOURCEID}
functions:
  example2:
    handler: index2.handler
    layers:
      - arn:aws:lambda:us-west-1:[myaccountid]:layer:example-layer:1
    events:
      - http:
          path: api2
          method: get
  example3:
    handler: index3.handler
    layers:
      - arn:aws:lambda:us-west-1:[myaccountid]:layer:example-layer:1
    events:
      - http:
          path: api3
          method: get

After first deploy, if I do

aws lambda get-function --function-name example-apis2-dev-example2 
...
"LastModified": "2021-10-27T06:30:31.002+0000",

and

$ aws lambda get-function --function-name example-apis2-dev-example3
...
"LastModified": "2021-10-27T06:30:31.987+0000",

Now if I make a code change only to the example 3 Lambda and redeploy only that function with:

serverless deploy function -f example-apis2-dev-example3

… example2 has not been modified since the first deploy (same timestamp as the original deploy):

$ aws lambda get-function --function-name example-apis2-dev-example2
...
"LastModified": "2021-10-27T06:30:31.002+0000",,

and only example3 shows it was updated/redeployed:

$ aws lambda get-function --function-name example-apis2-dev-example3
...
"LastModified": "2021-10-27T06:33:17.736+0000",

serverless deploy : deploys the whole stack (but if nothing has changed there is no update)

serverless deploy function -f functioname: updates just the code on that one Lambda (and updates in a couple of seconds vs several seconds for updating the whole stack).

This is described in this article here.