The IRS Where's My Refund? tool updates every 24 hours. This is normal, I would check back frequently, it sounds like they are working on your return.
If you claimed an Earned Income Tax Credit and/or an Additional Child Tax Credit and filed before February 15, 2019, you’ll get your refund the week of February 27 at the earliest. The IRS states they will begin issuing tax refunds on returns with the EIC or Additional Child Tax Credit on February 27, 2019.
According to the IRS on taxpayers claiming Earned Income Tax Credit or the Additional Child Tax Credit- https://www.irs.gov/pub/irs-pdf/p2043en.pdf
Claiming the Earned Income Tax Credit or the Additional Child Tax Credit
If a taxpayer is claiming the EITC or the ACTC, they can file
their return any time after the filing season begins. However,
by law, the IRS cannot issue refunds before mid-February for
tax returns that claim the Earned Income Tax Credit (EITC) or
the Additional Child Tax Credit (ACTC). Keep in mind that only
a small percentage of total filers will fall into this situation.
While the IRS will process taxpayer returns when they are
received, it cannot issue related refunds before mid-February.
The IRS expects the earliest EITC/ACTC related refunds to be
available in taxpayer bank accounts or on debit cards starting
on Feb 27, 2019, if they chose direct deposit and there are no
other issues with their tax return.
Some 2018 federal refunds will be delayed due to the PATH Act
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