It may be a pH issue. If that is mostly peat moss, the soil medium is likely too acidic. When pH is too low or high, the plant has problems up- taking nutrients, so it appears as a deficiency
Soil is too hot, the EC level is too high, it’s nutrients burn. You might not be using enough water on the watering and not getting enough drain coming out from the pot or might be using too many nutrients.
The soil is rich with nutrients. The leaf tips brown and curl up and in when this is happening. Do not fertilize for a bit. Only use ph water. Good luck and happy growing