Affiliates Pro tracks hit but GravityForms Integration doesn’t register referral

Here’s the setup:

WordPress 3.9.2
Affiliates Pro 2.7.1
GravityForms 1.8.11
Affiliates GravityForms Integration 1.0.1
Gravity Forms PayPal Add-On 1.10
Groups 1.4.10
Groups Gravity Forms Integration 1.2.0

Hits to a referral link are being tracked as going to the correct affiliate.

Referral timeout is set to 30 days. So, my intent is that when a buyer later purchases from a GravityForms form with Affiliates integration enabled, even if the buyer didn’t click a URL with the affiliate parameter in it, the purchase should still be attributed to the affiliate who referred them earlier.

But that’s not happening. The referral is attributed to the Direct affiliate instead.

The other steps are working correctly: a user is created and added to the correct group, the PayPal purchase goes through, the user gets an email with login info.

The only part that’s not right is the purchase referral is assigned to Direct instead of the affiliate who referred.

I’d appreciate your help in sorting this out. Thanks.