leave it alone for now and see what happens worse case the main root died and the baby can draw nutrients off the older one just a thought tho i'd be afraid to kill it if I cut the main root doo what u think is right
The Cryptocoryne species are often afflicted by what appears to be a sort of "melt". It is referred to as "Crypt Rot" or "Crypt Disease". But in reality it is rather from a shock of being transferred to a different tank, than being any "disease". Cryptocorynes very are sensitive to changes in their environment, such as transferring them to a new tank, changes in pH, etc ... The leaves may melt or rot away at first, but don't throw out the plant - it will re-grow with time. Once it settles in, it will be fine. Only keep cutting off any dying and decaying leaves.