Couple of remarks:
* we do not support forked deployments, if you did some fixes or added new features, consider making a pull request in order to review and merge in main tree and have the devs team trying to help on related issues
* uac module is not designed internally to send keepalives, so I guess you do something via kamailio.cfg , which means it is not an issue in the code, therefore it should not be reported via issue/bug tracker, but discussed and sorted out via sr-users@lists.kamailio.org mailing list. It is not a problem with kamailio code, but something about using kamailio.
Considering the above, I am closing this issue.