Diagnosis
Correct. The screen has a matte anti-glare coating. Harsh chemicals will permanently damage this coating, creating smears or dull spots.
How to Fix It
Power off the monitor. Use a dry, soft microfiber cloth. Gently wipe the screen in one direction. For fingerprints, dampen a corner of the cloth with distilled water. Wring it out completely. Wipe gently, then immediately dry the area with the dry part of the cloth.
If That Didn't Work
For stubborn spots, use a monitor-specific cleaning solution. Spray it directly onto the microfiber cloth, never onto the screen. Ensure the solution is labeled safe for anti-glare or matte LCD screens.
Heads Up
Never use paper towels, tissues, or rough cloth. Never use ammonia, alcohol, acetone, or window cleaner. Pressure can damage the panel. Always turn the monitor off so you can see the dirt clearly.