Hi, I am new to the forum. I had been after a tetrastigma voinierianum for some time and finally tracked one down to a Dutch seller. All was going well with watering and humidity ( not the easiest of plants to accommodate in this department) , new shoots etc, and then I had some home improvement done , plasterers, painters etc. During this time I neglected my routine and later noticed the leaves were drooping. I returned to my old routine and it seemed to perk up a bit. But then the leaves started to develop black shiny marks in the vein area. This is not some sooty mood as it won't wipe off. I have sprayed it with Bayer fungus fighter and although there is no evidence of insect attack I have treated for bugs. Despite rigorous internet searches I can't find any photos of similar and all references say the plant is very disease resistant. Can anyone identify the problem please ? I am posting a pic of the marks.