This is a user community forum that works like a bulletin board. I see you already asked this question earlier at this link:
https://ttlc.intuit.com/community/taxes/discussion/tax-calculation/01/1375528
You have to wait until someone sees your thread and feels like they can add to it, and at this time of night, few people are using the forum.
I'm a fellow user, not a tax expert, but I can tell you what might be causing that and how to look.
You appear to be using the Home and Business Edition, so is your income from self-employment? i.e., is the $12,000 your net self-employment income? If so, is the tax you are seeing due to self-employment tax? Self-employment tax is a separate tax, calculated separately from income tax, even when there is no income tax liability. Here's how to look:
Go into Forms Mode. In the left column list of forms pull up the Schedule SE. It may be abbreviated as Sch SE. It should show you the amount of your self-employment tax.
Then while still in Forms Mode, pull up Schedule 2 and look at Lines 4 and 10 of that form, which also shows the amount of your self-employment tax.
Then while still in Forms Mode, pull up the Form 1040. Look at the amounts of Lines 15 and 16.
After looking at all that, does self-employment tax explain what you are observing?
Also see these 2 FAQ:
FAQ: What is the self-employment tax?
https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/01/25922
and
FAQ: Why am I paying self-employment tax?
https://ttlc.intuit.com/community/self-employed/help/why-am-i-paying-self-employment-tax/00/26648
