Resource kubectl_manifest update failure

We are using the kubectl_manifest plugin to create the k8s resource. Terraform Registry

The resource is getting created but when we are trying to update the resource, we are getting below error.

Error: Provider produced inconsistent final plan
2022-12-14T16:27:46.7760091Z When expanding the plan for
2022-12-14T16:27:46.7760526Z module.argocd_apps.kubectl_manifest.argocd_apps["prod-ap-southeast-2"] to
2022-12-14T16:27:46.7760919Z include new values learned so far during apply, provider
roduced an invalid new value for
2022-12-14T16:27:46.7761722Z .yaml_body_parsed: .

We looked into the issue & checked the plugin source code as well. Plugin has the below implementation and we are getting below trace -

“yaml_body value interpolated, skipping customized diff”

As per my understanding, during an update terraform will call the plugin provider CustomizeDiff. And as per the implementation, CustomizeDiff is calling terraform helpler NewValueKnown function but it is returning false. And if it returns false, then plugin simply returns. As a result, resource is not getting updated.

I am trying to understand why terraform is returning false and what is expected from the plugin ?

CustomizeDiff: func(context context.Context, d *schema.ResourceDiff, meta interface{}) error {

		// trigger a recreation if the yaml-body has any pending changes
		if d.Get("force_new").(bool) {
			_ = d.ForceNew("yaml_body")

		if !d.NewValueKnown("yaml_body") {
		log.Printf("[TRACE] yaml_body value interpolated, skipping customized diff")
			return nil

@apparentlymart any idea what could be the issue ?