Why my philodendron xanadu has yellow spots?

It's so easy to make mistakes when caring for our plants! Overwatering, low humidity, and pests are the usual culprits. A straightforward way to check the soil is to use a humidity tool. It'll tell you whether it's dry or lacking moisture. If it's safe, take a peek under the leaves. You never know what might be lurking! If you do spot pests, don't fret. Give your plant some extra TLC by wiping the leaves or stems with pest alcohol.

I think your plant might have some uninvited guests—mealybugs and spider mites! You could try treating it by isolating the affected plant and manually removing it with a cotton swab soaked in rubbing alcohol or insecticide soap.