White stains on some leafs

Hi! some of my plant´s leafs have white stains on it, I wonder if thats heat stress or some nutrient burn, I really don´t know.
Thx for caring, here are some pics:

The tips of the leaves looked like mine when they were in the sun and had water on the leaves, light burn....although it could be a nute related burn. The last pic you posted has some light spots on the leaves, i have a bit of that as well, I'm guessing an insect of some sort, but I don't see any on mine even underneath the leaves

they were burned when they were emerging. that's old damage. it's brown and crinkled. the plant looks fine. you're forgiven.