Hey, buddy! 👋
I was looking for the exact composition of your Rubicon fertilizer, but I couldn't find any information at all. It's sold with the label "all included." I went to the official Rubicon website and found out that they use this fertilizer for cultivating cannabis. So, this fertilizer should contain all the necessary elements. You're applying a decent amount of it, so I think it should be enough. But if the plant is showing you a nutrient imbalance in its tissues, it can only be due to incorrect soil pH and watering!
You need to check the soil acidity and adjust your watering to 6.3 pH. You should have that 6.3 pH in both the soil and the watering during the flowering stage! 👆
Good luck, buddy! ✊😇