No, it's not normal.

It's powdery mildew. It needs a fungicide on BOTH sides of the leaves. A good spray bottle like this will be needed: https://www.amazon.com/VIVOSUN-0-2Gallon-Sprayer-Pressure-Sprayers/dp/B07QTHF9ZT (Suggesting this one since I have four and they work extremely well.)

Please read the following article for an intelligent way to combat the problem: Powdery mildew - Outdoors

Whatever you do, do NOT use any type of oil on the leaves, whether it be neem or horticultural - it NEEDS a legitimate fungicide.

This would be a better sprayer.

Also, you would only use about half to 3/4 of that sprayer for your apartment. Mixing at 10gs is fine.