IRS sent me a refund based on unemployment

[bsilverttt]

Dec 5 2021 I received a IRS Notice CP21B for 2020 that I'm geting an $835 refund. It doesn't say why, but I think its for the $3,796 of unemployment compensation I received and paid taxes on because I filed in Feb 2020. I need to enter the new Federal AGI on my Connecticut return to get a refund from CT who also taxed the UC. How do I get the new Federal AGI? The Notice does not say how the 1040SR was changed. 

Can I update - amend - my turbo tax return? And when I review my tax form in turbo tax it does not point out the "error".

[Bsch4477]

If you update your program the correction for the unemployment payment deduction should be made automatically to both federal and state returns. 

[bsilverttt]

That's what I already did, accepted update. Then reviewed return. It said everything was right 

[bsilverttt]

Again went through the update process, reviewed both Fed and CT return. Turbotax did not change anything.