Sometimes it takes a while for deposits to post to your account. According to the IRS website, "It takes additional time for refunds to be processed after leaving the IRS, and for financial institutions to accept and deposit them to bank accounts and products like debit cards."
If you don't see your funds within five days of the government approving your refund, the IRS recommends contacting your financial institution to see if your deposit was received.
Reference: IRS.gov - Refund Timing