2021 TaxCaster Standard Deduction - adds $1700 for over 65 not $1350

When trying to estimate taxes for 2021 using the Tax Calculator-TaxCaster, the std deduction appears to be incorrect.

 

For Married Filing Joint the std deduction is set to $25,100.  After setting age to over 65 it jumps by $1,700 to $26,800.  Then it jumps by $1,700 again to $28,500 with spouse also set to over 65.

 

For 2021 isn't the extra deduction amount for over 65 supposed to be $1,350 not $1,700?

 

Using $1,350, the std deduction with both over 65 would be $27,800.  Why is TaxCaster setting it to $28,500?