Vanilla plantifolia yellow leaves

[Vusi]

Hello

My name is Vusi from Johannesburg South Africa. I’m so happy to be part of this forum.
I have been growing a vanilla plantifolia from a cutting and it did root and had a new vine growing to almost a meter in length. I have kept it indoors where it can get outside sunlight. My troubles then started when winter settled in and the cutting leaf started turning yellow to brown. I reported it and cut off the new vine from the mother plant. It seems like everything just went from bad to worse. New growth on top of the vine fell off followed by young leaves turning yellow to brown. The stem looks healthy but the leaves have gone from dark green to a light green with a yellow tint. What can I do? Please help.