Gdax inconsistent with coinbase?

Gdax bookkeeping is a nightmare. They only have a history of buy/sell, no mention of transferring to binance. I have to rely on the coinbase transaction history. A couple wks ago I deposited $100 to gdax. A couple days later $200. Both show as "transferred funds to gdax" the next week. Today I use gdax to transfer that $300 to binance in the trade/BTC-USD screen. I press the withdraw button and specify my binance deposit address. I press MAX where I thought it would convert $300 to btc. While bookkeeping i realized only $98.46 was transferred to binance. My gdax account is empty. Am i misunderstanding or did $200 vanish?