I've had this problem too, so I created a test affiliate account and bought something through the link. The email below is the copy of the affiliate payment I received. It originally landed in a spam folder - which isn't terribly surprising. There's not any clear indication as to what the payment is for, or who it is from.
(see screenshot below)
Ask them to check their email in the spam folder, and search for this "from Use Fedora Inc." in the subject line.
note: this payment was received almost 2 months after the company name change to Teachable.