Transferring crypto

I’ve been in crypto about a year, I haven’t made many transactions though.

I bought more Solana last week, via Coinbase, intending to send to my Phantom wallet. When I try to transfer it says, “I don’t have any accounts from which sending is allowed. Try adding balances before adding sends.”

But I very obviously have Solana. I know sometimes the transactions aren’t instantly processed, but I deposited and bought SOL, the money left my account days ago, so any sort of hold would seem absurd, being a week.

Why is this an issue??