PR https://github.com/ManageIQ/manageiq/pull/10038 has been backported to the 5.6.1 branch. Will likely need to work with QE to try to validate this as it has been very difficult to reproduce.
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://rhn.redhat.com/errata/RHSA-2016-1634.html