Adding staff note to fee/fine increases fee/fine remaining balance for patrons with other outstanding fees/fines

Overview:
Steps to Reproduce:

1. Log into Kiwi Bugfest as an admin
2. Locate a test patron that currently has a fee/fine balance > 0
3. Charge the patron a manual fee/fine (see attachment Error-step1.jpg)
4. Go to Fee/Fine Details and click on "New staff info" button
5. Enter and save staff info
6. Note that the Action for the fee.fine has increased in balance (see attachment Error-step2.jpg)

Expected Results:
No change in remaining balance of fee/fine.

Actual Results:
Increase in remaining balance of fee/fine. It appears that all outstanding fees/fines for the patron are being added to the remaining balance of the one fee/fine.

Additional Information:
If the patron currently has no other fees/fines, this error does not occur. It only happens for patrons with other fees/fines.

Interested parties: