F5 Config Sync Issues

I had this problem in past more than once. It's a well known problem and there are hotfixes available to solve this problem.

I will have to restore the configuration database. Look at this Stephan Manthey's procedure from this topic. That should work, but you have first to disable the auto-sync in your device group in order to ensure that the just restored database don't overwrite automatically the cluster configuration and, of course, make a backup of your configuration. If you don't apply the hotfix you may have to repeat the procedure periodically as I had to.