[Bug]: aws_lb_listener_rule forward action missing in state

[liad5h]

Terraform Core Version

1.6.6

AWS Provider Version

5.34.0

Affected Resource(s)

aws_lb_listener_rule

Expected Behavior

I believe that the forward array in the state below should not be empty.
This results in terraform asking to update the action.forward blocks on every plan and apply

Actual Behavior

{
      "module": "RESOURCE_NAME",
      "mode": "managed",
      "type": "aws_lb_listener_rule",
      "name": "test",
      "provider": "provider[\"registry.terraform.io/hashicorp/aws\"]",
      "instances": [
        {
          "schema_version": 0,
          "attributes": {
            "action": [
              {
                "authenticate_cognito": [],
                "authenticate_oidc": [],
                "fixed_response": [],
                "forward": [],
                "order": 1,
                "redirect": [],
                "target_group_arn": "CORRECT_ARN",
                "type": "forward"
              }
            ]
          }
        }
      ]
    }

Relevant Error/Panic Output Snippet

no errors

Terraform Configuration Files

variable "actions" {
  type = object({
    forward = optional(object({
      target_group_arn = optional(string)
      target_group = list(object({
        arn = string
        weight = optional(number)
      }))
    }))
  })
}

resource "aws_lb_listener_rule" "this" {
  listener_arn = var.listener_arn
  priority = var.priority

  dynamic "action" {
    for_each = var.actions.forward != null ? toset(["forward"]) : toset([])
    content {
      type = "forward"
      target_group_arn = var.actions.forward.target_group_arn
      dynamic "forward" {
        for_each = toset(["forward"])
        content {
          dynamic "target_group" {
            for_each = var.actions.forward.target_group
            content {
              arn = target_group.value.arn
              weight = target_group.value.weight
            }
          }
        }
      }
    }
  }
# rest of the resource is not relevant

Steps to Reproduce

Create a listener rule for the ALB with the following tfvars

terraform.tfvars:

actions = {
  forward = {
    target_group_arn = "TARGET_GROUP_ARN"
    target_group = [
      arn = "TARGET_GROUP_ARN"
    ]
  }
}

run terraform apply twice, on the second run it will want to add the forwrad block again.

Debug Output

No response

Panic Output

No response

Important Factoids

No response

References

No response

Would you like to implement a fix?

None

[github-actions]

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[github-actions]

This functionality has been released in v5.36.0 of the Terraform AWS Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!

[github-actions]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.
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