Sometimes tribute letters do not automatically get added to payment records. In these cases, you can go to the Letters tab and manually add a tribute letter. Once you do this, the payment should pull into the tribute acknowledgement process with the corresponding letter. However, manually added tribute letters are not pulling into the Tribute Acknowledgements process.
When manually adding the tribute letter onto the payment record, do not add an acknowledgement date. This will make the Tribute Acknowledgement process think the letter was already run and doesn't need to be pulled in.