How to update lambda function code if the lambda code is uploaded to S3

The lambda function code(zip file) is currently being got from my S3 bucket. However, after I change my code and replace the original zip file with updated code and then run update-stack, the lambda function code seems not change in the lambda console.

Is there any way to make it work?

My json template

{
   "AWSTemplateFormatVersion": "2010-09-09",
   
   "Parameters": {
    "storageS3Bucket": {
      "Type": "String",
      "Default": "myBucket"
    }
  },
   "Resources": {
     
    "s3BucketImageStorage":{
      "Type" : "AWS::S3::Bucket",
      "Properties" : {
          "BucketName" : {
              "Ref": "storageS3Bucket"
          }
        }
    },
     "getBannerHandler": {
       "Type": "AWS::Lambda::Function",
       "Properties": {
         "FunctionName": "getBanner",
         "Handler": "getBanner.handler",
         "Role": {
           "Fn::ImportValue": {
             "Fn::Sub": "${RolesStack}-LambdaRoleArn"
           }
         },
         "Code": {
           "S3Bucket": {
             "Ref": "HandlerCodeS3Bucket"
           },
           "S3Key":"getBanner.zip"
         },
         "Runtime": "nodejs12.x"
       }
     }
   }
 }