Can someone explane me that when we send bitcoin to an exchange it most of the time takes a while, (1.5hours), but after 10 minutes i get i sign that the transaction is marked as confirmed?
Looks like your exchange is waiting for about 9 confirmations until you can access your funds. They're making certain that they are not going to be victims of a double-spend. Now when you spend your BTC the exchange sends it out right away. If you're in the first block then you'll see the transaction in 10 minutes or so.