If it's been longer than 21 days, and the IRS tool says it is still "being processed," then you're sort of in limbo.
In "normal times" you could speak to a live agent at the IRS to see if they can tell you anything about the delay. Perhaps they were planning to send you a letter or need additional info. Unfortunately, due to the Coronavirus situation and many IRS personnel sheltering at home, a lot of processing at the IRS has been suspended, correspondence is markedly limited, and their call centers are all but shut down for the time being.
The IRS says on their website:
"To protect the public and employees, and in compliance with orders of local health authorities around the country, certain IRS services such as live assistance on telephones, processing paper tax returns and responding to correspondence are extremely limited or suspended until further notice."
