BDS query.get_equipped_item_name always returns null/empty string

This code works fine in Windows 10 single-player:

{
  "format_version": "1.10.0",
  "animation_controllers": {
    "controller.animation.appletest": {
      "initial_state": "default",
      "states": {
        "default": {
          "transitions": [
            {
              "eating": "query.is_using_item && query.get_equipped_item_name('main_hand') == 'apple' && query.item_in_use_duration >= 640"
            }
          ]
        },
        "eating": {
          "on_entry": [
            "/say i've eaten an apple!"
          ],
          "transitions": [
            {
              "default": "!query.is_using_item || query.item_in_use_duration < 640 || query.get_equipped_item_name('main_hand') != 'apple'"
            }
          ]
        }
      }
    }
  }
}

The exact same code is completely broken in BDS 1.16.20.03. Any custom items that require the get_equipped_item_name query no longer work due to it always returning a blank string.

I also tried the most basic test in a custom animation controller:

{
  "format_version": "1.10.0",
  "animation_controllers": {
    "controller.animation.appletest": {
      "initial_state": "default",
      "states": {
        "default": {
          "transitions": [
            {
              "eating": "query.is_using_item && query.get_equipped_item_name('main_hand') == 'apple'"
            }
          ]
        },
        "eating": {
          "on_entry": [
            "/say i've eaten an apple!"
          ],
          "transitions": [
            {
              "default": "!query.is_using_item"
            }
          ]
        }
      }
    }
  }
}

This doesn't work either. query.is_using_item is working only by itself. As soon as I add query.get_equipped_item_name, it breaks because of the empty string.