Since it's only been up and running for such a short amount of time, I bet it's due to the sword being replanted. Give it a couple weeks and I bet it will come around. Just trim off any leaves that melt and I'm sure they'll be quickly replaced.
If it continues past several weeks, then you may have an issue. You'll also need to provide more info, such as the size of the aquarium, CO2 levels if being used, ammonia, nitrite and nitrate levels, hardness, alkalinity and what fertilizers are being dosed along with their frequency.
If it continues past several weeks, then you may have an issue. You'll also need to provide more info, such as the size of the aquarium, CO2 levels if being used, ammonia, nitrite and nitrate levels, hardness, alkalinity and what fertilizers are being dosed along with their frequency.