Chinese (Napa) Cabbage (Sui Choy) Seeds

What's happening to my chinese cabbage?

I planted my chinese cabbage seeds on 4/22/26. They germinated well and all appeared good in terms of growth. The plants are about 6" tall and leafy, but a flower head is already growing in the center of each plant. If I'm not mistaken this is usually a sign the plant is ready to produce seeds.

As expected. Great germination rates. Packaged well.