What causes this funky taste difference between beef from different stores?

I love beef, and I’ll grab anything that looks well marbled when I’m grocery shopping around. But for years I’ve noticed a very distinct taste difference between beef from different stores to the point where some cuts become almost inedible for me and I end up getting most my meat from just 1-2 stores to prevent waste.

Pattern I’ve noticed:

• Costco/Walmart/Sams almost always tastes fine never has that off flavor
• Japanese markets also typically fine too, and I'd typically get the same cuts as Korean.
• Albertsons/Safeway is hit or miss. Sometimes meat would be fine here, sometimes pretty bad.
• Korean markets (H-Mart, etc., with beautiful marbling and fancy beef sections) despite their fancy meat sections, marbling, and premium price are for some reason consistently mostly the worst for me, taste-wise, even though the meat looks great.

The issue is this specific gamey/metallic/iron-y flavor. My wife calls it “funky.” It’s not spoilage and it’s there even when the meat is perfectly fresh and marbled. I notice it the most in nontypical steak cuts like sirloin, filet, flat iron, etc.

What is this