Script does not exit
Hmm, there seem to be some confusion here. Quit is under option 9, not 0. Selecting the quit option works as it should (At least on cachyos, I don't have Fedora installed). What version of BashBurn does this fail on for you? Version 4.0.0 can be downloaded from https://sites.google.com/view/bashburn/downloads (And should work fine).
Thanks for reporting. Will fix and push a new release soon
Quick patc h attached. Error caused by setting the recurring option under password expiration even if expiration was set to 'Never'.