How do I stop missing defects I should catch?

You keep missing defects you feel you should have caught, and each miss stings because the standard you hold yourself to is right there. But do not turn this into proof that you are bad at the job. Catching defects is a trained skill, and right now you are being asked to see things your eye has not yet learned to see. Most misses are not from not caring. They come from not yet knowing exactly what to look for, or from checking in a loose, unstructured way that lets things hide. When you learn the specific signs of each common defect and check in the same deliberate order every time, the things that used to slip past start jumping out at you. The seeing is teachable. Ask someone experienced to show you exactly what the defects you keep missing look like, then check for those on purpose, every time, in a set order. You are not failing. You are learning to see, and with a clear target and a steady routine, the catches will come.