"If a grant was returned by 12/31/20 then it should not be reported on a 1099 for 2020."

I know that the national news commented on large employers taking SBA grants, PPP, etc, and then returning them. The public Cares funds disbursed through the county and States are different, though. The grants were taxable, already. That's why an issuing entity might use a corrected 1099-G. But the receiving entity cannot force nor expect this, and now that the perspective is flipped, you would contact the grantor. They might have turned the disqualified portion into Debt, until repaid.