Yellowing Vanda leaf... can someone help me ?

[Gchatzfamily]

We've only had our vanda a few months. It came with two flowers spikes. One in bloom and one still in buds. The first spike that was in bloom has started to brown and some of the flowers have slowly started to fall. From what I've read this is normal. The other flowers spike with the buds has opened is in bloom right now no issues. The problem is with two leaves. One is right under where the browning spike is and the other in way down at the bottom by the roots. They are turning yellow then brownish black. I thought at first this was sunburn so I got a shear curtain to protect it from direct sun. However the last few days the brown has been spreading faster even though it's been behind the curtain. Help me please if you can identify what's happing to my vanda please let me know I am open to all advice and recommendations. I've attached some pictures of my issue. Thank you