I think you are right it is young and also it probably was growing in a closed environment so the leaves are burning. When I first got mine the leaves burned and I had it in a bathroom with no window.

The first year I grew it in almost total shade and I did get some browning on the edge of the leaves. The fourth year growing I did not get any burning at all. I think this is a plant that needs to mature before it is strong enough to support the varigaited leaves.

Another hint to growing this plant. It likes being in bog conditions. I never let it dry out and it grows without any browning. It was beautiful this year.