2021 TurboTax does not allow "deceased date" of a deceased tax payer that is in 2020. (I received 1099's in his SS number for 2021.) Do anyone have a solution to this?

He should have an estate for 2021. The IRS does not allow someone to continue to have a personal tax return after the year of death.

Contact the payer to have the payments and the Forms 1099 corrected and reissued in the name of the proper beneficiary.

If the money was paid to a designated beneficiary, the payer needs to reissue the 1099s.

If the money was paid to the deceased after their death, then it was really paid to their estate.  The estate must file a separate tax return called a form 1041, not a regular form 1040.  You can prepare the 1041 with Turbotax Business, which is a PC only program on CD or download (not online and no Mac version).  

Here are some links,

https://ttlc.intuit.com/community/choosing-a-product/help/which-turbotax-do-i-need-to-file-a-return-for-an-estate/00/27230

https://ttlc.intuit.com/community/my-tax-return/help/how-do-i-file-form-1041-for-an-estate-or-trust/00/26382

https://www.irs.gov/businesses/small-businesses-self-employed/deceased-taxpayers-filing-the-estate-income-tax-return-form-1041

I have an EIN for the Estate. Do you know if I need the 1099's (issued to his personal SS) re-issued to the Estate EIN?

Yes, you should request that the 1099s be reissued in the name and EIN of the estate.