Brown part of Dendrobium Rigidum leaf: Something wrong?

[Bulbopedilum]

One of the oldish leaves of my Dendrobium Rigidum has developed this strange dried brown area. Is this just a dry part or is something wrong? Should I remove the leaf? It is not mushy or wet.

[estación seca]

The leaf is dying; it's your job to figure out why. I don't think it's a natural end-of-lifespan issue, since the leaf looks like it was very healthy very recently.

It might be too little water - dead roots - too low humidity (probably not, where you live) - too high humidity - too much sun - many other things.

[Bulbopedilum]

Originally Posted by estación seca

It might be too little water - dead roots - too low humidity (probably not, where you live) - too high humidity - too much sun - many other things.

Strange thing is that every other leaf on the plant looks perfectly healthy.
Too little water: Probably not, it's succulent-ish and I give it water every 2 days

dead roots: Probably not, the other leaves on the rhizome-stem are fine.

too high humidity: The vendor would also have pretty much the same humidity as me. So no.

too much sun: Could be, it gets a high-ish amount of sun from about 7:00 AM to 8:00 AM, but probably not. Again, the other leaves are healthy.

Is this a disease that spreads perhaps? Should I cut off/remove the leaf?

Further Investigation:
It could be shipping damage. This picture is taken from a photo of the plant right when it arrived.

[estación seca]

Is this one of the older leaves? If yes, I would just let it dry up and fall off. This doesn't look like a fungal attack to me.