to All Things Plants!
I don't know a thing about Bauhinia variegated but leaf problems on many plants can be caused by over-fertilization, cold damage or too low humidity. I've read that Bauhinia variegata is considered deciduous or semi-deciduous and loses it's leaves during in the dry season so perhaps the leaf issue is normal for where you live. Whatever the case may be, I hope your Orchid Tree recuperates and grows well for you.