Elon Musk’s much-hyped interview of former President Donald Trump on the social media platform X was quickly derailed by technical glitches in the first minutes of the scheduled start time on Monday evening. Social media users trying to log on to the event, which was scheduled to begin at 8 p.m. ET, reported that they could not join X’s livestream platform. Shortly after 8:20 p.m., Musk, the billionaire Tesla and SpaceX CEO, blamed a cyberattack for the freezing screens. He said that the company had tested the system with 8 million concurrent listeners earlier on Monday to preempt any technical...