Thanks for reporting this, Kai Zheng.
TestBlockTokenWithDFSStriped already uses MiniDFSCluster with random port settings and 49333 is the randomly chosen port. It could be race with another process using ephemeral port.
TestDFSZKFailoverController seems to use fixed port settings because zkfc part does not allow random port setting. Let me see this if you do not yet started the work.