I have this, what I think, problem on my Paph. The bottom leaf is turning brown in colour. I'm not sure if this is problem or not since this is my first Paph. The tip of the leaf at first was a bit yellowish and in last week started to turn dark brown. As you can see from the attached photos the part of the leaf where it's attached to the main body is also affected. This Paph I purchased last March and have never flowered. It is very slow growing. I used magnifying glass to inspect the plant and I couldn't find any bugs or anything like that. I don't know if this is some kind of fungus or..... I didn't inspect the roots as I was told by the seller that I shouldn't disturb the roots.
Any help in solving this is welcome and appreciated.
Thanks,
Slobo