I too tried this tutorial and got the same result, just a big moving blob/chunk.
I see 2 unclear steps…
- I noticed there is something plugged into the material opacity mask… but no mention of opacity mask in any of the steps.
- I noticed there is a 2nd link going from the first LinearGradient but no mention of where that goes (and plugging that into opacity mask does nothing).
Maybe an completed view of the entire material would help.