I ran into this same issue at one of our clustered sites (55 total locations). I could only solve this by doing an upgrade on the software, or reloading the software on the box. After reloading the software/upgrading (13.0.80 to 13.0.83, a while back), I was then able to perform a backup. After doing said backup, the audit failure alarm cleared. I do not know of any other way to clear this audit failure, unfortunately. I worked with a Mitel Senior Systems Engineer in troubleshooting this prior to upgrading. As long as the 13.X version is not different, i.e. 13.Y, it will still communicate and sync with the rest of the cluster without issues.
DBMS check/save is good, but will not clear the audit. The ONLY way to clear this is to perform a successful backup. Hope this information helps!
Gene