Struggling with Dendrobium — would appreciate advice

I want to be honest: I'm not getting great results with Dendrobium and I'm not entirely sure why. scale insects on pseudobulbs and undersides of leaves has been a recurring problem despite my attempts to address it. I've been focusing on repotting into fresh bark medium every two or three years based on everything I've read.

extraordinary bloom longevity lasting weeks to months is there in glimpses, which tells me the plant has potential in my conditions. I have it in a grouping with other tropical plants for humidity which might not be ideal. rest period in summer with focus on leaf and root growth showed some improvement. Two stars for now — not the plant's fault, but not a success yet. I'll update if things improve.