Is this a correct diagnosis? Brown leaves with white spots

[Orchid Whisperer]

For some reason, when I first looked at the original post, I could only see 2 photos through the link.

I am leaning more in the direction of your original diagnosis, or possibly Ray's. I would absolutely cut the leaves back to healthy green tissue. Sterilize blade between cuts. I would keep the plant on the dry side (possibly careful watering of the roots, absolutely no water on the leaves).

I don't really use cinnamon, but you can try it (leaves only, never on roots).

I would not spray with peroxide. After a dry period, and observation to see if the problem spreads, you can wipe leaves with a paper towel moistened with peroxide.