What happened to this violacea leaf?

[PaphLover]

I've swabbed it with alcohol. No red dots (thinking mites).

It was under a light and on a heat mat for a while…could it be heat stress? And why are only one or two leaves affected? …it's been growing a new leaf that looks shiny and healthy.

It does have three drops of clear 'happy sap' or honeydew on the flower stem at the old flower nodes.

I'm getting mixed signals, violacea. I can't tell if you're happy or unhappy.