One leaf on cattleya is yellowing

[SakuraDrops]

Hello all,

I bought this cattleya at a workshop in August.
I have not repotted it. It has since had new growth since then, but I am concerned about this leaf turning yellow/brown. Could this mean anything?

Please see photos here: Unsure cattleya - Album on Imgur

Care:
Outdoors under 95% shade cloth
Temperatures vary 85-95F, fans blow on the leaves all day
60% Humidity
Fertilize thoroughly each month, probiotic every 2 weeks
Water every other day, it rains sometimes, and also I will water on consecutive days.

Any help is appreciated , thank you!!