Yes. ALL of your income has to be entered on the same tax return. Your refund or tax due is calculated based on the total amount of income and tax withheld from all of your income.
WHY DID MY REFUND GO DOWN WHEN I ADDED ANOTHER W-2?
You started off with your first W-2 and your refund looked high? Then you added another W-2 and it stopped looking so good? That is normal. When you added more income, your tax liability increased, so you saw your refund decrease. The program began by giving you your standard deduction—- which lowered your taxable income. So you are not being taxed on as much of the income on that first W-2. Then you added taxable income--so the refund went down. Your refund (or tax due) is based on the total of your income, not “per W-2.” Wait until you have entered ALL of your income and credit/deduction information. You can't really tell anything until it is all entered. That “refund monitor” does not mean anything until everything has been entered.
They should be. Did you enter them both into the same tax return Before you filed? The total of W2 box 1 should be on your 1040 line 1.
Before filing, You can preview the 1040 or print the whole return
How to get a copy after filing