To visit his parents in eastern Shandong Province in January, for the first time since the coronavirus pandemic began, Mr. Xue, 37, had already shelled out $7,600 for airfare. He had submitted negative test results to the Chinese authorities, as required for entry. Upon arrival, he would have to do three weeks of quarantine.

Even so, he never could have foreseen just how much of an ordeal he was about to suffer. Mr. Xue, through a Kafka-esque streak of bad luck and run-ins with China’s unbending virus rules, would spend the next three months in quarantine, bouncing between hospitals and hotel rooms.

Released from one round of isolation, he would immediately find himself ordered into another. By the time of his return flight, he would have had about two days of freedom in China. He would not have seen his parents at all.