You might want to check if you have a T4A slip with boxes that are triggering a self-employment income report. Please check the flowing link:
https://turbotax.community.intuit.ca/community/navigating-turbotax/help/why-is-turbotax-telling-me-i...
If you have a T4A slip, you report the income once on the business sheet T2125 > do not report the slip separately
From the Find engine on the top bar > search Business Profile or Business and Professional Activities, depending on the product you are using > it will open the Business T2125 sheet questionnaire
I hope this was helpful
