Sounds like they are tightening the nuts and then running the valve to see if the torque is working.
Dumb Question: Don’t they know what the correct torque is on the nuts and don’t they have torque wrenches?
Hydrogen’s so tiny that, under high pressure (this is liquid H), it will leak out of anything. This is a major reason that the Saturn V was RP1 and LOX (just like the V2, and Falcon 9, and a number of others throughout the world and since WWII), with the cryofueled upper stages requiring much smaller tanks (and with some use of hypergolic fuel, which stores easier and longer).
This Artemis is a Shuttle-derived vehicle, and like the Shuttle main tank, the load-and-go takes much longer to accomplish due to the sheer size. However, you’d think a derivative of a successful vehicle would A) not cost the effin’ Earth, and B) be much easier to develop. This is a uselessly duplicative capability that costs too much, and is (thus far) unproven.
The first orbit of the Moon by Artemis 2 is supposed to be crewed, and in 2024. My guess is, best case will be at least a year late, and more probably, it will never be completed, having been overtaken by events, such as the SpaceX behemoth that had a 14-engine static fire in the past day or so.
https://www.youtube.com/watch?v=r4XzEmbdtLM