Chuck Banas on "[Plugin: Seamless Donations] Entryfields aren't populated on the custom 'Thank You Enhanced' page"

Using the 'Thank You Enhanced' add-on/plugin. Post-transaction, the custom 'thank you' page is displayed, but the entryfields aren't populated. For instance, the text reads:

"Thank you, , for your generous donation, in the amount of $."

I seem to have everything configured properly. I've tued-on debug mode. I also tried it with the 'ignore nonce' feature enabled and disabled. I disabled the theme and tried it with one of the standard WordPress themes. I disabled all plugins except the Seamless Donations ones.

Specs:
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PHP 5.6.16
cURL 7.46.0
OpenSSL/1.0.2e
Wordpress 4.5.3

SSL is properly configured on server and in WordPress (sitewide).

In addition, at some point in the last day or so, the Seamless Donations Log stopped populating. Also, the Seamless Donations settings page still reports that "https:// IPN URL does not respond" even though SSL works, the link resolves, and PayPal transactions work perfectly. I'm thinking these last two symptoms may have something to do with the fact that the entryfields aren't populating, but after two days of troubleshooting, I'm at a loss.

I can provide links to the dev site, but I'm reticent to post this stuff publicly for security reasons.

https://wordpress.org/plugins/seamless-donations/

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