My refund went down when I went to e-file signifigantly. How do I fix it?

That sounds pretty weird.   Did you e-file successfully?   Was the return accepted?   Where were you seeing the refund you thought it would be?   And where did you see it go down?   What were you seeing on the "refund monitor" before you e-filed?   What is on line 35a of your Form 1040?

One guess---did you go through the Federal Review at the end and enter the stimulus check you received in 2021?   If you received the third EIP payment of $1400 per person in 2021, you cannot get it again as a recovery rebate credit on your 2021 tax return.   Did you refund go down by $1400 per person?