I remember you mentioned spring sickness maybe because of the "ribbon like" leaves I had.
I cut those fans (I left 10 cm from the ground) and they are slowly growing, but the new leaves show that holes too. When I cut the leaves I felt with my hand that they were really "hard", I don't know how to explain it. Like a sort of thin wood.
One of these DLs emitted a new fan that is completely healty, deeper green, no signs on leaves.
Some leaf has that saw tooth ragged edge, yes, really near to the ground, and a rust color.
These two DLs never disappeared during the winter.
I just fertilized them with a liquid fertilizer, soil was very dry I didn't give much water so it's not really humid. I was expecting rains but no rain came until now.
New leaves didn't get freezin temps I guess, near 0°C.