[aws-events] `cdk diff` shows difference, but `cdk deploy` tells no changes

I’m not sure whether this issue is involved with aws-events or cdk diff.

Reproduction Steps

I have deployed this resource:

import * as events from '@aws-cdk/aws-events'

new events.Rule(this, 'rule', {
  eventPattern: {
    detail: {
      type: ['대한민국'], // Any non-single byte characters
    },
  }
)

cdk diff always tells there is a difference even though it has been deployed.

$ cdk diff <stack>

Stack <stack>
Resources
[~] AWS::Events::Rule rule rule5EE78A73 
 └─ [~] EventPattern
     └─ [~] .detail:
         └─ [~] .type:
             └─ @@ -1,3 +1,3 @@
                [ ] [
                [-]   "????"
                [+]   "대한민국"
                [ ] ]

But when I tried to deploy again, it tells:

$ cdk deploy <stack>

<stack>
<stack>: deploying...
<stack>: creating CloudFormation changeset...

 ✅  <stack> (no changes)

What did you expect to happen?

$ cdk diff <stack>

 ✅  <stack> (no changes)

What actually happened?

$ cdk diff <stack>

Stack <stack>
Resources
[~] AWS::Events::Rule rule rule5EE78A73 
 └─ [~] EventPattern
     └─ [~] .detail:
         └─ [~] .type:
             └─ @@ -1,3 +1,3 @@
                [ ] [
                [-]   "????"
                [+]   "대한민국"
                [ ] ]

Environment

• CLI Version : aws-cli/2.0.45 Python/3.8.5 Darwin/19.6.0 source/x86_6
• Framework Version: aws-cdk 1.62.0
• Node.js Version: v14.9.0
• OS : macOS Catalina
• Language (Version): TypeScript 4.0.2

Other

---

This is 🐛 Bug Report

[timasplin]

I was facing the same issues on a different resource when trying to update the DeletionPolicy - but I found this in the CloudFormation documentation: https://docs.amazonaws.cn/en_us/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-get-template.html

Important You cannot update the CreationPolicy, DeletionPolicy or UpdatePolicy attribute by itself. You can update them only when you include changes that add, modify, or delete resources. For example, you can add or modify a metadata attribute of a resource.

[jdiegosierra]

Same problem changing ONLY DeletionPolicy