Welcome to the Exchanges subforum, where you'll find people making similar complaints about other exchanges as well.
GDAX has been plagued by constant downtime and API dropout recently, although in my experience, Kraken is even less reliable. The CEO made a statement last month, and it was the typical excuse: "We're victims of our own success." And I'm sure it's true -- more new users and money are pouring into this space than ever before.
Even some of the old standbys like Bitfinex have become unreliable and glitchy. I saw a complaint yesterday on Reddit where a user tried to withdraw USDT. They accidentally charged him a 2BTC withdrawal fee (instead of a 2 USDT fee) and as a result, a bunch of his margin positions were liquidated. Unacceptable, but also no surprise.
Deal with any exchange at your own risk right now.