Is this brown rot on my Paph?

[CROrchid]

I've noticed this (photos attached) on my Paph. malipoense. Keep in mind that the black/dark brown spot just near it was already present when I first purchased the plant online. I tried poking it with a q-tip to feel the texture of the spot, it's firm and dry and does not seem mushy or wet? Humidity in my growth space is rather low (rarely above ~45%) and temperatures are around 22*C. I do (unfortunately) water plants in the evening/night as this is when I have most time available.
What do you think? Is rot supposed to be wet/mushy or not?

(In case it needs to be done, I can use a small pair of scissors to cut that leaf out, it's still very firmly attached to the plant)