Here are the steps to properly configure a custom receipt within Receipt Manager:

Notes for this configuration:
1. “Create PDF Receipts” must be checked to generate PDF Receipts.
2. “Create PDF if no deductible” is optional – check that if you want a PDF Receipt generated for transactions with no tax deductible amount.
3. “Attach PDF Receipts to autoresponder” should be checked if you want PDF Receipts attached to transaction autoresponders.
4. “Always process uploaded PDF receipts” does not apply to your configuration.
5. “PDF Receipt Template Filename” can be anything you like, but we generally recommend “receipt.pdf” or something similar.
6. “PDF Receipt Provider” must be set to “CUSTOM” to enable Receipt Manager.
7. “PDF Receipt Template” must be set to your “default” PDF Receipt Template, which will be used for all transactions in all campaigns and events unless there is a different Receipt Manager Template assigned.
8. “PDF Receipt Upload Task Interval” does not apply to your configuration.

The reason why a default receipt was still sending was because step 6 was likely still set to "default" and not custom"