modeladmin.message_user in async admin action

Using Django The Admin
1

I’m trying to run a admin action async but I’m unable to print a message after the function finished using modeladmin.message_user().

As a workaround, I currently run the async code inside the function with async_to_sync() but I would like to run it async if possible.

Using this code, the message does not get printed:

@admin.action(description="Re-Sync selected customers from API")
async def sync_customers(modeladmin, request, queryset):
  """Sync the selected customers from API"""
  for customer in queryset:
    customer = await api_client.get_customers(customer.id)
    await save_customer(customer)
  await sync_to_async(modeladmin.message_user)(
    request,
    ngettext(
      '%d customer was successfully synced.',
      '%d customers were successfully synced.',
      len(queryset),
    ) % len(queryset), messages.SUCCESS)

However this works:

@admin.action(description="Re-Sync selected customers from API")
def sync_customers(modeladmin, request, queryset):
  """Sync the selected customers from API"""
  for customer in queryset:
    customer = async_to_sync(api_client.get_customers)(customer.id)
    async_to_sync(save_customer)(customer)
  modeladmin.message_user(
    request,
    ngettext(
      '%d customer was successfully synced.',
      '%d customers were successfully synced.',
      len(queryset),
    ) % len(queryset), messages.SUCCESS)

How can I fix this?
I use Version 5.1