What are the most common mistakes in system design interviews?

I've been doing a lot of mock system design interviews lately, probably around 15 in the last few months, and the feedback feels inconsistent. Some interviewers say I dive too deep too early, others say I'm too high-level. It's hard to nail down what the common mistakes are and how to avoid them. From my perspective, some common pitfalls I've noticed myself or gotten feedback on include: not asking enough clarifying questions at the start, over-engineering solutions for simple problems, or getting stuck on a particular component without considering alternatives. Sometimes I also struggle with structuring my thoughts within the time limit. What do you all think are the *most* common mistakes you see candidates make in system design interviews, and what's the best way to course-correct? I'm trying to identify patterns so I can improve more effectively.