Sunburn from direct sun

What's happening

Stromanthe evolved under the dappled shade of the rainforest understory and isn't built for harsh, direct sun. When strong rays hit the leaves through a window they scorch the tissue, leaving dry, faded, brown-to-bleached patches that don't recover — usually worst on the variegated cream areas, which have less protective chlorophyll, and on the leaves nearest the glass.

How to fix it

Move the plant back from the window or to a spot with bright, indirect light, or filter the harsh sun with a sheer curtain. The scorched patches won't turn back to color, so trim badly damaged leaves at the base if you want a tidier look; the plant will replace them with healthy growth once it's out of the direct sun.

This is general guidance based on common symptoms; individual plants vary.