It's always a headscratcher when 2 plants in the same environment exhibit differently. Every plant will have its slight varying nutrient profile. But more often than not you will find some environmental metric that has slowly built up over time. The pot closest to the air intake, or air circulation has a dead spot ornot enough oxygen in a pot. Maybe one pot is fabric and one is airpot, I'd be looking at pH myself.
Best of luck finding the issue.