Dendrobium papilio requirements

[Fredmax]

I've read most of the info on the web so thought I'd check if anyone has experience with this one. It's one of the only den species which is really struggling on me so have to think it has some non-standard requirements.

Since arriving it's been losing all it's leaves and is down to a handful, I initially thought it needed more water than others (as IOSPE says), but now I'm thinking it's the heat it can't deal with being a cool grower, but other similar cool growers are coping fine so this must be really sensitive?

It's got many other Den's growing fine (tiongii, devonianum, miyakei, tobaense, laevifolium, usitae , chameleon, unicum, aurantiiflammeum etc.) within 1 meter of it but this one's floundering on me.

Hoping someone else grows this