One Javascript code stops firing when another is triggered

My coworker and I are working on this page: http://ift.tt/2EaI9zI.

Because Blackbaud Netcommunity doesn't let us choose a dropdown display for the CFI Branch affiliation option, we thought we could write our own dropdown and sync it up with the checkboxes, then hide the checkboxes with CSS. (We have unhid the unsightly checkboxes for purposes of troubleshooting)

We got that part working but there is another piece of Javascript on that page that syncs up the One-time vs Recurring payment options. Whenever someone picks recurring payment and then adjusts the branch dropdown, the checkboxes no longer respond. The javascript for the dropdown/checkbox sync also doesn't work if the dropdown is adjusted after submitting the form with errors.

How can we restart this javascript file in these situations?