ACH (automated clearing house) payments (ie. direct draft from a checking account) can take up to 30 days to clear(…that is the funds can be clawed back from the merchant). So it is not unusual for a merchant (esp a merchant that is not familiar with you) to hold the asset until final clearance of the payment (precious metals vendors also do this). 

Having said that, Coinbase is imho likely involved in selling BTC they don’t own (fractional reserve/paper BTC) and price manipulation of said asset. Also imho they are one of real btc’s biggest enemies…so I personally wouldn’t transact with them. 

I have used Swan and River financial and settled on River. They are BTC only and very dependable. I’ve never had a hiccup purchasing (DCA or smash buys) and never had a hiccup transferring. I buy often enuf that my window to transfer has narrowed to a few days after purchase with ACH but in the beginning it was ~20 days, if I remember correctly. 


Fun fact: one of the final pieces to entering the  BTC rabbit hole for me was when I noticed while purchasing precious metals that my vendor displayed the following at check out:

All purchases with credit card and ACH payments will ship in 30 days, with wire transfers will ship in 3 days and with BTC will ship within 24 hours.
…Talk about a great advertisement for BTC😂🌅 

 I concur.  Coinbase tried to report on me.  They get what's coming to them...