Στίγματα

Did you spray something on the leads with some old fertilizer in it? Happened to me once > sprayed water that had some rooting hormone in it by mistake and my leafs look like that till I sprayed a few times... Could also be Powdery mildew

Yes as others have said - it’s from some water or solution being on the leaves and drying and leaving reside

Residue, as in stuff in water or the remnants of a foliar spray or pest prevention you may have used. That's what it looks like to me, as well.

Possibly residue from minerals in the water.

It impressed me. I don't think there's any deficiency. When you say residues, what do you mean? What could be left on the leaves?

Not the best picture and without a diary we don't really know what you got going on. It looks like possibly residue from a humidifier or residue from getting the leaves wet and it dried.