I don’t have explicit answers, Blender is as Blender does most of the time. If it gets quirky, I try to do workarounds if it’s misbehaving. For the time being, try not to focus on the weird things Blender does, it always does weird things and they don’t always have answers unless you are a super coder developer. Try sticking to the basics for now, place your seams where they should go on the model, don’t leave things without seams, then unwrap, it should go smoothly.
