A similar thing happened to me on Binance US with a small amount of money ($500) when I was first trying to get funds into Hive. They gladly and immediately accepted a deposit of USD from my bank. Then, when I tried to transfer out the tokens I bought, they locked up my account for several months waiting to "verify my identity."

Luckily, it was a small amount and they eventually confirmed my ID and released the funds after a few months, but it was extremely frustrating and I have never used Binance since.