what is wrong with my acanthephippium's leaf?

[Greenthumb.5]

The brown marking has been spreading but it seems dry. I just go this plant recently.

[Hiester]

Kinda looks like sun scorch to me, especially if the leaf is dry and light tan in color. Has this plant been exposed to full sun sometime recently? The sun can easily scorch young, thin, pliable leaves in a very short period of time. The effects might not manifest for a day or two, and then they can sometimes be progressive as the plant struggles to recuperate.

[euplusia]

I fear it's a serious infection, maybe bacterial. I'd cut the whole leaf off. Maybe it was triggered by rapid growth, nitrogen, warm weather, high humidity.