Thanks for answers guys. I knew Coinbase account doesn't support USDT, but I'm using Coinbase Wallet, which is a software wallet different than my coinbase exchange account. It's the equivalent of Metamask, Trust Wallet, etc.
Here below is a screen capture of my wallet, it definitely supports USDT, I have a small amount in it.
Where did you download wallet from ? it it from official coinbase website because the one I downloaded from coinbase google store does not support USDT. by the way, USDT have various blockchain probably you might have sent an OMNI usdt to erc-20 wallet or viz versa. you will need to check this before making transfer in case of future needs