The IRS is seriously backlogged due to all the new tax laws and extra stimulus filings, as well as unprocessed 2019 returns still left over from the COVID shutdown. Many states are slow as well.  Lots of other folks are still waiting (some since mid-February), so please continue to be patient.  Also see:

Overtaxed IRS Warns of Long Delays For Millions Of Tax Refunds (moneywise.com)

 IRS is holding millions of tax returns, delaying refunds (msn.com)