Broker cannot be restarted in shared fs master slave after network failure

I have two instances (A and B) in shared filesystem master slave configuration are deployed (A is master B is slave). When I simulate network failure between master and NFS server then B becomes master and A starts its shutdown procedure. A's shutdowns procedure throws exceptions related to I/O error (see attached log file) since kahaDB folder on shared NFS is unreachable and A does shut down.

But when I stop broker B (which is currently master), reestablish connection between A and NFS server and manually restart broker on A. Then it claims that DB is locked and broker on A will never start (which is bad especially in case that broker is restarted automatically by setting restartAllowed="true" in activemq.xml). Only solution to successfully start broker on A is to stop whole Fuse and start it again.

When debug logging is enabled on SharedFileLocker class it claims that:

08:42:19,559 | DEBUG | AMQ-2-thread-1   | SharedFileLocker                 | 140 - org.apache.activemq.activemq-osgi - 5.11.0.redhat-621032 | Database /mnt/nfs/fuse-shared/standaloneFaframTest/lock is locked... waiting 10 seconds for the database to be unlocked. Reason: java.io.IOException: File '/mnt/nfs/fuse-shared/standaloneFaframTest/lock' could not be locked as lock is already held for this jvm.

So it look like that A still holds the lock but it is not possible since in between B instance was a master.

Persistent storage configuration:

        <persistenceAdapter>
                <kahaDB directory="/mnt/nfs/fuse-shared/standaloneFaframTest/" lockKeepAlivePeriod="2000">
                        <locker>
                                <shared-file-locker lockAcquireSleepInterval="10000" />
                        </locker>
                </kahaDB>
        </persistenceAdapter>