Porroglossum meridionale leaf problem

[veefour]

I put P. meridionale in my vivarium a month ago. It has continued to produce blooms the entire time and produced 2 new pseudobulbs. However, one leaf turned reddish/purple along the edges, then it yellowed and completely died (it was a weird bright red when it fell off). Now other leaves are starting to do the same thing.

Is this sunburn, over watering, or disease?

Any advice/help would be greatly appreciated.

[WhiteRabbit]

[estación seca]

I don't know, but it looks to me like a plant that is getting far more light than it wants.