Let's talk about Affiliate attribution for a moment.
The information below is directly from the Teachable support page.
"Cookies" are used to prepare customized web pages or save user information. On Teachable, a cookie is created whenever a user clicks an affiliate link, regardless of whether or not they purchase the course at that moment. This cookie is valid for the "cookie period" (as determined by the school owner) or until the user's browser cache is cleared. School owners can set the “cookie period” for affiliate links.
I have set my school's “cookie period” at 365 days.
In practical terms, this means that even if someone clicks an affiliate’s link, leaves the site, and returns to purchase later—the sale will still be counted towards the affiliate (as long as the user is on the same device and browser, has not cleared their cache, and is within the cookie period).