The IRS is closed & they are not taking phone calls.  They are still processing e-filed returns & stimulus checks but they have been behind.

It is taking the IRS longer to process returns since they are closed.  They are still processing e-filed returns but the 21 days (business days) is not the standard now due to Covid-19.  The IRS is not processing mailed in returns at this time.

You can check the IRS website, Where's My Refund, for update on your Federal refund, the website updates once a day.  

https://www.irs.gov/refunds