lucene - Sitecore 7.5 ContentSearchManager (CD environment) index is empty when visiting from one hostname, but populated when from another -

i having unusual issue search indexes , contentsearchmanager in sitecore 7.5 when deployed on cd.

if use 1 hostname populated, hostname empty.

i have checked siteconfig , both hostnames in hostname list, , site responds both, search indexes keeps showing empty on 1 , populated on other.

any appreciated.

if need see configs , implementations, can show you, not entirely sure need, tell me, , show.

many