If I made a minor amendment to my return, adding some small ($139) 1099-Div data, Why has my federal refund (amending 2020) now dropped from over $2000 to $25?

[tfiks]

Does the new $25-refund figure on my amended return represent a separate refund or have those small changes reduced the net refund I'll get by over $1,975?

[VolvoGirl]

Have you filed the original return?  Do not amend until the first return is fully processed and you get the first refund.  The Amended 1040X return should only be for the difference you get back or owe.  Line 18 should be your original refund amount and line 22 should be your additional refund. If you paid on your original return it will be on line 16. If there is an amount owed with the amendment, it will be on line 20.

[tfiks]

Thanks, @VolvoGirl.
That seems logical, but I couldn't find anything on TurboTax explaining the disparity. I have filed the original return and it's been accepted.  I am a little nervous about letting the original, incomplete return sit with the IRS. When it's discovered that I left out income, won't the IRS reject the whole return? 
What puzzled me was the $25 refund figure on the amended return (which I haven't filed yet). Why would I get an additional $25 when the only change I made was added income and I didn't have anything other than some foreign tax deducted from that extra income?

[AmyC]

Let me explain more about the IRS. They accept your return based on SSN and birthdate kind of stuff. Then they process it based on the current criteria, checking stimulus, etc. Refunds issued. Then the return starts going through all the actual breakdown of everything on the return and cross checking the income and deductions. It usually takes about 3 years before the IRS notifies you of missing income. Then you pay interest and penalties for all that time.

Your amended return will be accepted before that happens to replace the missing income.

An amended return should be filed after the original is processed. Column A should match your original. Column B the changes. Column C the correct amounts. If the IRS does make any adjustments, those can be noted on the amended return. Sit tight for a little while.

[doc_wooster]

This is good info! I forgot to include about $24 in 1099 capital gains, and if I were to do an amended return, I actually lost money on that $24, so  no taxes are owed but of course, the IRS doesn't know that. Nonetheless, I considered filing an amended return, but now I will not. , I don't mind being dunned $4 for taxes either.