Either you've overwatered or there's a nutrient problem.
If your plant is getting too much water, it accumulates in the pot and the plant can't breathe. Some leaves don't receive oxygen and die.
Control and correct the pH and EC values
Both values need to be within the optimal range to ensure an optimal supply of nutrients to your crop. If the soil pH value isn't adjusted correctly, nutrients can't be processed properly in the leaves, leading to nutrient burn.
The optimal pH value for soil cultivation is between 6.0 and 7.0. Conversely, if the EC value is too high, your growing medium may be salinized, which can cause a blockage or nutrient deficiency.
What looks like a nutrient deficiency is actually a blockage in the soil. The plant can't absorb the necessary minerals due to the soil being oversaturated with salts.