This is an old thread but it may be beneficial for someone in the future. We had a very similar problem in our environment recently. Following the solution article https://support.f5.com/csp/article/K10066 resolved the problem. You need to stop the zrd and the named processes and then remove the relevant journal file(s). And then start the named and the zrd processes again. Stopping the zrd is harmless in regards to dns resolution. Stopping the named process will make your BIND unresponsive so you may want to do that in a maintenance window.