By default, affiliate referral links are generated using 7 random symbols (e.g., https://your-site.com/?ref=nlmjdis). When this option is enabled, your affiliates can also (by default) customize their affiliate links on their end.
To disable "default" links, all you have to do is go to Programs > Advanced:
Here you will find the option to toggle off the default referral codes.
This way, the codes will be replaced with the tap_a and tap_s parameters, like this:
