Are you mailed and claim a dependent on your 2030 return? Did you claim the dependent on 2021? You should have each gotten IRS letter 6475 saying what they sent you. You each get a letter for half. So I'm assuming you got a letter for 2100 and you spouse did too. 2100 is half of 4200. Which is the 3rd Stimulus payment for 3 people.
Double check your bank statements and Check your IRS account (both accounts if married)
Your Online Account | Internal Revenue Service
If the IRS thinks they sent it to you but you didn't get it request a trace for a missing third Stimulus payment
https://www.irs.gov/newsroom/questions-and-answers-about-the-third-economic-impact-payment-topic-j-p...
