Hello OutdoorOperations,
You are right, this is a nute problem.but not due too less nutrients. The plant can only absorb nutrients within a certain pH (acidity) range.
To bring the soil to a lower pH range you want to give water or a nutrient solution with the pH range that you want to bring your soil to.
So my advice is to water the plants now with 1 time the pot volume with water and nutrients and make sure that the pH is between 6 and 6.5 (6.2 is perfect). But you need to use a pH down supplement and an pH measuring tool to measure the pH.
You can buy a pH down supplement for 10 euro and a cheap chinese pH pen (measuring tool) for 20 euro.
When you do this your plant will be able to use the nutrients inside the soil again and will provide you with some big, fat and juicy buds!
Happy Growing Buddy! 💚