The lower leaves of this orchid has developed two irregular spots, one on each of two leaves. The center is papery thin and brown with black fringes, while the green parts are plump. The bottom leaf in this picture also has an irregular dried part, but seems slightly different than the black spots. The top leaf in the picture has those pale speckles around it, but the other one doesn't so that's sorta weird.
I'm guessing it might be sunburn, but I'm not ruling out disease or viral infection.

Any suggested course of actions, or just leave it as is?
Thanks!