The Critical Power Graph is broken again for me after it was fixed around 18 months ago. I have what I believe is very old data back in my graph. Years ago I started Zwift on rollers with zPower. This was not accurate as I could maintain the maximum 400W with a high cadence. It was garbage data and I couldn’t up the resistance.
I bought a smart trainer and deleted my old data that had a flat horizontal section on the power curve at 400W.
Now my old data seems to have returned and the power curve is useless unless I delete all my years of Zwift power.