Not authorised to update WAF Managed rule set

Hello,

I can across an issue with the IAM policy used for the lamba function when it attempted to update the managed rule set on the managed rule set.

This is the error I received:
Error: An error occurred (AccessDeniedException) when calling the UpdateWebACL operation: User: arn:aws:sts::xxxxxxxxxxx:assumed-role/xxxxxxxxxxx/xxxxxxxxxxx is not authorized to perform: wafv2:UpdateWebACL on resource: arn:aws:wafv2:ap-southeast-2:xxxxxxxxxxx:regional/managedruleset/

To overcome this issue, I applied the following to the CFN template.
- Effect: Allow
Action:
- wafv2:UpdateWebACL
Resource: !Sub 'arn:aws:wafv2:${AWS::Region}:${AWS::AccountId}:regional/managedruleset/*'

Is my workaround the best approach and is this expected behaviour?

Start by inspecting the CloudFormation template's IAM policy for the Lambda function and the permission used for the WAF UpdateWebACL operation. Compare the existing resource scope with the reported managed rule set ARN and determine whether the proposed permission is expected and appropriately scoped.

Written by the indexing model from the issue text.