The CRA considers amounts in box 20 and box 48 of the T4A slip as self-employment/business income.

If you entered a T4A slip in your return with amounts in box 20 or box 48, you must complete a Form T2125: Statement of Business Activities. Only minimal entries are required; the business name can be your name and the business address can be your home address.

You will need to "edit" the information that has transferred from the T4A to the Business Statement. To do so, go to:

• Income Tab > Self-Employment > Business & Professional Activities
• The box for "Professional, Commission, and/or Other type of business" should checked > Continue
• On T2125 Business Summary page, click "Edit" next to the business that appears there and make your entries.

https://turbotax.community.intuit.ca/replies/3282160

I have the same problem this year - got this message below that blocks Netfiling and yet I don't have any business income. We have a rental property in Florida, so put in the US address.  It was no problem for the past 7 years.

Any advice?

Did you solve your problem? I have the same problem, however I had some business income. My business address is the same as my residence address.