If you had the fees deducted from your refund that would leave about 4200 missing. That sounds like the 3rd Stimulus payment (1400x3 people). The IRS records show they already sent it to you.
Do you have an amount on 1040 line 30? You might have tried to claim it again. Line 30 is only if you didn't get the full amount or qualify for more.
Double check your bank statements and check your IRS account (both accounts if married) to see what they sent you. Check both IRS accounts if married.
Your Online Account | Internal Revenue Service
