Is it possible for the plant to outgrow the hot soil(if thats the problem)? I.e. ...if the plant gets big enough, will the "hot" soil become just normal in a sense? Because of the plant being much bigger?
Before doing the following, I would check all other possible issues like pH, light intensity, temps, etc....
If if if and only if the soil is determined to be the cause, I would get known good soil. Then, carefully remove the plant from the current pot with the entire rootball intact. Then, very gently massage and loosen up the existing soil. Then, gently rinse the rootball with hose to remove as much existing soil as possible. Then, carefully transplant back into container with new known good soil. Then trim back some of the damaged growth, being sure to leave the lower new growth shoots intact. Then, put under lights at reduced light intensity to allow less stress while plant adjusts. Then, slowly increase intensity back to original level over the following week.
I say "gentle" a lot because you want to preserve the integrity of the roots as much as possible.
The already damaged growth will not improve, but if you get the situation fixed, then the new growth will look healthy.
Good luck! Peace
![Peace :peace: :peace:](/styles/smilies/peace.gif)