Fan leaves will naturally yellow and die as the plant progresses, it's part of their life cycle just like human cells die and regenerate. As long as it's not huge swathes of your plants dieing at once it shouldn't be a problem. Whatever you do don't remove green fan leaves though, unless they're blocking light to a nice bud or something. Even then, I feel it's better to cut off the end half of the fingers rather than pulling the whole leaf off. I don't even remove yellow fan leaves because the plant will reuse as much of the leaf as it can (chlorophyll, sugars, misc. nutrients). I wait until they start to brown and get a bit crispy, by then the veins in the leaf which would transport nutrients to the rest have dried up and/or collapsed. I keep these brown leaves to pack in a vape or make hash from or something. Wouldn't want to smoke them though.
