On your T5013, do you have anything on Box 104 (partner code 5), Box 116, Box 120, or Box 122? These require you to fill out a Form T2125 Statement of Business or Professional Activities (self-employment) form.
Here is more info from the CRA on the T5013: https://www.canada.ca/en/revenue-agency/services/forms-publications/forms/t2125.html
