What about the amount you are having withheld?
No one in this user forum can see your tax return. or your screen. There were major tax law changes that began with the 2018 tax year that seem to continue to surprise some people. Personal exemptions of over $4000 per person were removed beginning with 2018 returns.
One thing that may be affecting your refund for 2019 is that employers began withholding less tax when the new tax law passed. Your paychecks were more, but that means a smaller refund now.
There are are lot of variables that affect your refund or tax due including how much you earned, how much tax you had withheld, your filing status, the number of dependents you claim, your deductions and credits, etc. You may have lost Earned Income Credit or the Child Tax Credit— did a child turn 17? If you received the EIC last year, remember that changes in the amount you earn have a big effect on the amount of EIC you can get. (Sometimes earning more money means less EIC) Are you 65 or older ? If so, your standard deduction is higher. Everyone has a higher standard deduction now so it is harder to use itemized deductions.
And of course, always check your own data entries, looking for errors such as misplaced decimals or extra zeros.
Tax code changes, increase in income leads to changes in tax brackets. Ideally you would want to receive no refund at all and owe no taxes so that you get to keep more of your income each pay period.
However, if for some reason you want to give the US government an interest free loan of your income, then increase the amount of taxes that are being withheld from your wages so you will receive a large refund.
You will have to change your W-4 that you give to your employer for tax withholding.
Go to this IRS website for a W-4 withholding calculator - https://apps.irs.gov/app/tax-withholding-estimator