Application is not working on public url configured on IBM IHS.

Hi Team,
I have configured CLM on distributed topology using WAS Liberty server. I have used IBM Http Server (IHS) as a reverse proxy server and its working fine on public URL.
But the problem is that when I restart the physical server/box merged plugin gets changed and application do not follow IHS. I am not getting why the plugin contains is getting changed. I works fine with WAS.
Anyone can help me on this.
Awaiting your response,
Krunal.