Avatar stops when above 200w

When free riding, my avatar comes to a stand still when my power goes above 200w. Why is this? It extremely frustrating. My son uses the same set up and it doesn’t do that for him - he can way past 200w (ie 400w) and his avatar keeps going. Why does it happen to me?

You’ll need to provide a whole lot more information about your set up to get any meaningful information about this situation.

Spin bike, with wahoo cadence and speed sensors. HRM. Prior to this week, my avatar did not stop. All I have changed is the bike type from my garage. TT to mountain bike. Does this make a difference?