More details are likely needed here ----- as in history. Eg. was the orchid in that growing area for a long time? Or did it just arrive, such as by shipping. And if it was in the growing area for a long time, then were there any relatively fast temperature changes, or was there any extreme temperature event (cold event, or very hot event). etc.
At this time, I agree. Maybe could apply some systematic ------ no guarantees. Eg. copper spray.
The bark looks a bit dry there too.