No one would know why your return says "still processing", not even TurboTax. Only the IRS (or State) has the answers. "Being processed", means the IRS must first process your return and then approve your refund. It's possible your tax return may require additional review and take longer.
You can keep checking the IRS website, Where's My Refund, they only update once a day, usually at night, so checking it more than once day will have no changes.
