Bumping this to 3.11 since we are fixing for the ES5.x. We may need to provide a backport should 3.10 and earlier continue to be troublesome
In v3.11, There is only one .searchguard index. so the issue won't happen.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2018:2652