New status SIGNED for charge

[ivanov17andrey]

A few days ago appeared new status SIGNED for charges. Also, it's not described here.
How to interpret this status?
Code used

client = CoinbaseCommerce::Client.new(api_key: COINBASE_API_KEY)
client.charge.retrieve(charge_id)[:timeline].last[:status]

Also, it started to return an error on charge creation if local_price.currency = 'usd'. Before it worked with lower case, now it accepts only upper case 'USD'.

client.charge.create(
    local_price: {
    amount: payment.calculate_amount,
    currency: payment.currency.upcase
    },
    ...
)

coinbase_commerce (0.8.7)
rails (6.1.3.1)
ruby 2.7.7p221