The reason is the crawler contraption [ there is no other way to describe it ] that is used to bring the SLS to the launch pad. The hydrogen leak is from the crawler's hydrogen fueling station to the rocket. The crawler was built by 2 separate contractors: the first was let go without passing on its blueprints, documents to the second contractor, who failed to turn over its blueprints, documents etc, leaving NASA's engineers to figure out any fixes blindly. So there are problems that may not be fixed ever, just patched. The is a remote possibility that Artemis will die on this sword.
After THREE YEARS, how did NASA fail to fix a leaky rocket?! HINT: It's not the rocket!
https://www.youtube.com/watch?v=3ojqpDt7xZ0
