I am not using web wallet much, unless I am in need of some quick money to cash. That's why I was having a little BTC to my coinbase wallet. Yesterday, when I sent ~0.06 BTC which I was holding there for a long time, they didn't send it instantly. They emailed me that it will be delayed since they need to check the transaction for some reason.
It's very common for exchanges to hold someone's balance which aren't spent for a long period of time that's why holding your assets are not recommended to be held by an exchange otherwise it can result you in a scenario like this. On the other hand, you may just use an application based third party wallet instead such as Electrum for your convenience.