Box 028 of the T4A slip is to add other income, which includes amounts that are not reported anywhere else on the T4A slip. Yes, this can be for the summer job you performed during 2021, if it is a form of other income which is different from your regular income. 

For more information visit Canada Revenue Agency (CRA) website - T4A slip

Ok   

Then when I place the number into Turbo Tax and answer yes or no to their question. 

Turbo Tax now thinks I am self-employed?  Which I am not. 

  Ugh    Is this a bug?     Thank-you 

what should I do now?

Yes - this is a bug.

The TurboTax software incorrectly assumes that a T4A Box 28 entry implies not only self-employment but that you have an actual business running and won't let you proceed without filling out forms - e.g. T2125B's. 

The bug is still present even 2 years later. 

This is the last year I use TurboTax

Please see the image below to enter your T4A box 28 so it is not counted as self-employment.

Thank you for choosing TurboTax.

Same thing happened to my son. He worked a casual job and received a T4A slip with the amount in box 28. He is not self employed, but it is asking him now to declare that he is and asks for an upgrade. If the request for upgrade is ignored, he gets an error at the end. SO ANNOYING!

Please see the image below to correctly enter the box 28 of the T4A information slip in the return. Please choose No to indicate the income is not for self-employment and that there were no fees charged for services.

Thank you for choosing TurboTax.

The graphic you provide is not the same as what i see in my TT application.  I was hoping it would be but I have multiple box 28 options and I am still prompted to complete forms for self-employment.  I already have redone the taxes 3 times thinking there was something I was doing in error.  I would leave out the $675 but I know that is asking for a lot of trouble from Rev Can.

Can you send us a picture of what you see so we can further assist you? 

Thank you for choosing TurboTax.