Exceso o Deficiencia de calcio? DWC

Good afternoon, colleagues! I would like to see if you could give me a hand with this, honestly, it's giving me a lot of headaches. First of all, let me explain how things are going. I started to notice these spots on the leaves, I removed them, and now the new leaves have stagnated in growth and the same spots are coming back. I thought it was a calcium deficiency, so I drained and put in a new nutrient solution with osmosis water (17 LT) (ec 0.0). I supplemented with Sensi Cal Mag to raise the ec to 0.35, then I added 15ml of Rhino Skin to strengthen the plant against pests and heat (it doesn’t modify the ec). I also applied 15ml of B-52 (ec 0.40). As a base fertilizer, I use Solo Tek Grow from Grotek, raising the ec to 0.8. After that, I raised the ec to 1.0 with Monster Grow, and I also use Great White Myco. I manage a pH range of 5.57 to 6.15 and vary within that pH range. My grow room stays between 25 to 28 degrees at most. The humidity is at 58% to 65%. All the plants are in the vegetative stage, and this is the only one giving me headaches. I forgot to mention, when this problem arose, the roots were stagnant in growth, but after changing the nutrient solution, they started to grow again at a better pace, although a bit slowly, but the top of the plant is growing very slowly. The nutrient solution stays between 22 to 26 degrees; I can't lower it more than that. The lighting is LED CREE CXB 3590 320W at a height of 50cm. I also applied a fungicide on Sunday to see if it was a fungus; I applied a foliar application on the roots and leaves just in case. Reading on a Yankee forum, I found that it could be a phosphorus deficiency, but I doubt it. The genetics is a CHOCOLATE MINT OG from HUMBOLDT SEEDS. I'm leaving the photos of the spots that are driving me crazy, and I hope you can give me a hand.