When your guitar buzzes, check your fingers before you blame the guitar.

Checking yourself first is quicker and usually right. A buzzing string nearly always means a finger slightly off the fret rather than a fault in the instrument, and reaching for the outside explanation ends the search before it starts. Blame pointed outward is comfortable and gives you nothing to work with. Looking at your own technique is the only version that leads to a fix.

When something is not working this week, check your part before anything else. Grip, posture, whether you read the instructions, whether you actually did the step. If it still fails, then go looking further out.