I haven't watched the video but just looking at your sketch, this vertical constraint is causing some of your issues. You have to be careful when the auto-constraint option is enabled. You'll end up with constraints that are not intended and can be difficult to find.
If you intend to maintain constant material thickness thru this section, the radii must be concentric. I much prefer to keep the radii as separate features, in most cases, rather than extruding or revolving them due to the amount of complexity they add to sketches.
