USDT TRC20 Deposit Not Credited on Gate.io
As with other exchanges, a Gate.io deposit that seems missing is usually either still confirming on-chain or already confirmed and waiting on internal crediting.
Verify on TronScan
Search your transaction hash on TronScan. A confirmed SUCCESS to Gate.io's correct deposit address means the funds have reached them — the remaining wait is on their side, not the network.
Check the network used
Confirm the deposit address generated in your Gate.io account was specifically for the TRC20 network before assuming anything else is wrong.
Contacting support
With a confirmed on-chain transaction and an unusually long wait, reach out to Gate.io support with the transaction hash as evidence.