What is wrong?

I have some alocasia frydek corms in pon, some older than others, and all of their newer leaves have turned out like this. I let their reservoir dry out for 1-2 days, making sure there is still some humidity inside, then refill to about 1/4 again. They sit in a southern facing window, but blinds half open so they receive dappled full sun. Any suggestions on what may be causing this?? ❤️