I've read about and heard from people that have had some issues. Usually it's the bank that is the issue. They don't like people withdrawing money to be used in something they don't have their grubby little fingers in, i.e cryptocurrency exchanges.It was told me to only invest unspent beer money in crypto. The returns look good on paper but getting the money out is not a simple task. Some places take it, but its always been just murky enough to scare me off.
I can't think of any exchanges that I use that don't allow me to deposit money and begin trading immediately. There is a waiting period before I can withdraw said funds again tho.
Mostly depends on how long ago it's been since I last made a deposit. 4-6 business days is what I typically see on Coinbase. The time varies by whatever exchange you are using tho. I had to wait 65 days to move some crypto off of Uphold. Something like that's almost always because of the exchange and their asinine way of doing things, not because of whatever particular cryptocurrency you bought.