electrum: blockchain.scripthash.get_balance does not work for Liquid

I am testing the Electrum websocket interface of Esplora, the method `blockchain.scripthash.get_balance` it seems to not work

`blockchain.scripthash.listunspent` works just fine for example, I guess `get_balance` can't be implemented due the confidential txs? In my test, I am using a scripthash that has non-confidential utxos on it.