I think another problem is the humidity! 90-100% ist just too much.
Most highland Neps love 60-80% in the day and around 90 in the night. Is there any way for you to change the hymidity?
I do not think that lighting causes the damage. Hamata turns red very very easily. Before the light would cause dying leafs and brown spots the leafs would turn red.
My adavice: Reduce humidity and don't let the night temperature drop too far below 10°.
Maybe even get them a bit more light. The pitchers are not fully colored up.
Niklas
