https://bugs.openldap.org/show_bug.cgi?id=9847
--- Comment #1 from Howard Chu hyc@openldap.org --- If the behavior is different between daemon mode and foreground mode, it sounds like you need to investigate why these two modes are different on OpenBSD. I.e., you have a OS/platform issue and there's unlikely to be an OpenLDAP software issue to be fixed here.
kqueue support is known to work on FreeBSD and MacOSX so again, you need to find out what OpenBSD is doing differently.