Why is my investment income, reported as other income Misc 1099 being reported on schedule C and i have to pay self employment tax on it?

You can enter the 1099-MISC in TurboTax as "Other Common Income. Please use the following steps:

1. Click on Federal > Wages & Income.
2. Scroll down to the Other Common Income section.
3. Click on the Start/Revisit box next Form 1099-MISC. 
4. On the screen Did you get a 1099-MISC?   Yes 
5. Enter the information from the 1099-MISC.
    
6. On the following screens, answer the following questions:
   • Did it involve work that's like your main job? No.
   • You got it in 2021
   • No, it didn't involve an intent to earn money

 7.  Continue through the rest of the interview screens. The income will appear as Other Income.

Here's the general procedure for viewing the forms list and deleting unwanted forms, schedules, and worksheets in TurboTax Online. You can use this to delete the 1099-MISC being reported on Schedule C:

1. Open or continue your return in TurboTax.
2. In the left menu, select Tax Tools and then Tools.
3. In the pop-up window Tool Center, choose Delete a form.
4. Select Delete next to the form/schedule/worksheet in the list and follow the instructions.