[SR-Users] Kamailio does not delete expired contacts

Hi everyone, I am using Kamailio-4.1.5. I met a problem that Kamailio does not delete expired contact. I enable log file for module usrloc and see that, about 1 first hour, timer callback of usrloc module working fine (delete all expired contacts). But after that, it is not called --> Expired contacts in shared memory and database are not deleted. I configured usrloc module like that: # ----- usrloc params ----- modparam("usrloc", "db_url", DBURL) modparam("usrloc", "db_mode", 2) modparam("usrloc", "use_domain", MULTIDOMAIN) modparam("usrloc", "db_ops_ruid", 1) Could you help me to fix this problem! Thanks so much!