I think I can eliminate spidermites (never had them before, but no signs of them on the plant), other sucking insects in the folds, and I do not grow it anywhere near the light I have.
However:
3) I do keep it right on the windowsill during the day. It is possible that it might have touched the cold window (it's still pretty cool here in southern Ontario) though not probable. My thermometer near the window usually reads in the higher 70s. It's odd that the leaf right below it is not affected at all, though.
4) There is some more discolouration where the leaf meets the stem. It's not soft or wet. I only water the moss that the plant is in, but it's possible that some water got in there before I acquired it (pictures below) Could I treat it with Hydrogen Peroxide?
5) Could be a root problem, but no visible roots yet
One other thing is that the affected leaf is not nearly as "open" as the others. The tip is still a tight "V"
Was your oderata still a seedling when you repotted it? I am itching to repot mine, actually. I just don't want to set it back.
Thank you so much for your help
I'm still very new at this.