Wormholes are considered an advanced topic among the many fields of knowledge in interstellar civilizations. Just as Iridium Star had once utilized stable wormholes for extra-long distance travel, they've also been tricked by unstable ones.
Wormholes connect two different spaces, not just a universe plane, but also possibly the void.
When the Golden Great Sail Ship came to the Second Universe, the wormholes connecting the three stations naturally allowed people to travel through with the Golden Great Sail Ship. However, the wormholes connected to the void weren't something just anyone could traverse.
Or rather, no one could. Members of the Elder Race don't count as people.
By this time, Bai Zhongqi had already realized that many people had not relayed information about the Elder Race, the main reason being that all those who boarded the Golden Great Sail Ship couldn't part with it and always wanted to make a final gamble, following the Golden Great Sail Ship into the void.