Nepenthes ramispina

This Nepenthes ramispina originaly comes from Borneo Exotics, I bought her on EEE in Prague as the size S. Although it now looks quite good, I have had a problems with this plants repeatedly. It always stopped growing and lost almost all leaves. I replanted it again and again when this happened and after 2-4 weeks it started to grow again. The roots are really weak, weaker than of nepenthes generally , and I still dont know what can I ecpect from this nepenthes. Plants in natural habitat have brighter leaves, as I saw on pictures of plants in habitat. It grows in really very lightsome habitats among stones and etc, which is a little unusually habitat for most of nepenthes. I don't think that the humidity here is very high. That´s why I want to try to place it to my greenhouse for dioneas and droseras in summer to confirm if this nepenthes really needs "only" very sunny place and "only" occasionaly higher humidity.