Thanks for adding those screenshot, Martin. I think they’re helpful in conjunction with the video.
Just for clarification:
All the things Martin pointed at are correct and addressed in the first 2/3 of the lesson, including different corner geometry, adding .25 bevel weight to all edges and why ( including between flat faces ), and turning off clamp overlap.
Those solutions are also aimed at fixing the material issue.
The only thing we don’t do in the lesson is applying the modifier, so we can stay flexible. 😉