newly added IPS are dissapperaing from whm after reboot

There is open case 62029 on this issue. It has been merged for the next 11.34 release. In the meantime, please run the following to resolve the issue
=================================

/usr/local/cpanel/whostmgr/bin/setupipaliases
/etc/rc.d/init.d/ipaliases start 

=========================

IP missing Show IP Address Usage

If IP missing Show IP Address Usage though you have added then in order to resolve this issue you need to restart the service :

/etc/init.d/ipaliases restart

issue must resolved. :)