What's going on and how can I stop this? I have no more details
I see signs of infection. Because they are very drought prone, I would not offer them any water, outside of rainfall. If you do not supplement at all anyway, then you may have to keep fungicides handy. Treat, very constantly.
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
Only reason could be that I bought a pack of seeds and used some from last year. I have just never seen the leaves look like that before. (The left plant in the pictures)
It is likely that hybridization has occurred from nearby plants, or past genetics are showing themselves. This is not harmful, but will lead to some interesting flowers over time. Eventually, over years, they may all solidify into a single set of genetics.
This article will offer some information on their care: