If you transfer funds to an exchange wallet on any shard other than shard 0, the funds will not reflect in your exchange account. Fear not, your funds are not lost! You will need to contact the exchange and provide them the corresponding transaction ID for them to help you fix the problem.
Go to your wallet (i.e. Math Wallet), and log into your account
Select your Harmony account, and then find transactions record
Select the transaction in question, and copy the transaction ID to provide to the exchange you're in contact with
Select the exchange you are using below, and that will lead you to their support page where you can submit a request your transaction ID to resolve the issue.