The amount of EIC you receive is based on how much you earned by working and your other income. You do not automatically get the "full" amount.
https://www.irs.gov/credits-deductions/individuals/earned-income-tax-credit/use-the-eitc-assistant
A $725 EITC does not line up with anything. Are you sure you are looking at your EITC and not your CTC or another credit? The EITC for a single person with one qualifying child and income of $28,191 would be $2,938. For one dependent, there is not a credit that matches the $795. There is a $1,795 if you earned $35,300- $35,350, but that would be the closest possibility.
For the EITC, as your income goes up, your credit goes up until it hits the top of the bell curve, then as your income continues to go up, the credit goes back down. If your income is going back down, your credit would slide back down the hill backwards decreasing your EITC. To get the full $3,995 you would have had to make less than $28,000 but more than $11,850. Your income is higher than that so your credit should be reduced.
Look at your form 1040 on line 27. This is where your EIC will be entered. You can also look on line 19 and 28 to see if this is actually the Child Tax Credit instead of the EIC or possibly another credit.
you can use the iRS EIC calculator to check
https://www.irs.gov/credits-deductions/individuals/earned-income-tax-credit/use-the-eitc-assistant
As you can see in the EITC Interactive Assistant that Mike suggested that there are a number of other components that go into the EITC calculation than what you listed above.
If you run the EITC calculator and still come up short, reply here and tell us all the other components so that we can help you work it out.