Hard to say from a distance ... but the marking is typical of too much root moisture. Fungus' and virus' are thoughts too far at this stage. Frankly I think that if your plant has survived this far then for sure it will survive.
Assume you have taken it out of the humidity. Don't be afraid to water and feed if yr grow material is well drained. Make sure yr grow material is draining well. Needs plenty of light now ...
Good Luck ...
"Life is ... a Continuum ... with no Beginning and no End. It is not going Somewhere ... it is always Here." Osho
"Human consciousness, at the same time as being a form of Awareness, Sensitivity and Understanding, is also a form of Ignorance.
The ordinary everyday consciousness that we have ... leaves out ... more than it takes in. And because of this it leaves out things that are terribly important. It leaves out things that if we did know them would allay our anxieties, fears and horrors. We would have a deep, interior Peace.
Now ... the question that is absolutely basic for all Human Beings is: What have we left out?