How to handle state values only used in Terraform that aren't returned from the backend?

I have a value in my resource’s schema that can be set to do some filtering on the Terraform side before sending the request to the backend. This value doesn’t exist in the backend so it doesn’t get returned on Read. Every time I do a plan or apply it shows a diff resetting the value.

      ~ page {
...
          ~ widget_table {
              ~ filter_current_dashboard = false -> true

I tried to suppress the diff like this:

	return &schema.Schema{
		Type:        schema.TypeBool,
		Optional:    true,
		Description: "Use this item to filter the current dashboard",
		DiffSuppressFunc: func(k, old, current string, d *schema.ResourceData) bool {
			return true
		},
	}

but then my value is never being set. Is there a preferred way to handle this?

This is the affected resource if helpful