Help !!

Some of the sprouts have suddenly started dying, drying up. Some leaves are losing one finger. Please see pictures. This is in a tent with 2 other Gold Leafs, all clones of a strain I am familiar with and have had easy times growing until this. It seems to me like it would have to be a bug or disease, with the plant being otherwise healthy until now. This is being grown in FFOF and recently was given it's first nutes, which it handled well. Any comments or ideas are more than welcomed. Should I quarantine this plant until I know and have handled the problem? Thanks !