Hello everyone, sorry to disturb but can anyone pl...

Boron deficiency, either by too little boron or too much calcium magnesium which in high doses prevents boron uptake. B deficiency is considered as a nutritional disorder that adversely affects the metabolism and growth of plants. B is involved in the structural and functional integrity of the cell wall and membranes, ion fluxes across the membranes, cell division and elongation, nitrogen and carbohydrate metabolism, sugar transport, cytoskeletal proteins, and plasmalemma-bound enzymes, nucleic acid, indoleacetic acid, polyamines, ascorbic acid, and phenol metabolism and transport. Nothing else can make such a dwarf. Cell elongation is next to zero. The prevalence of symptoms depends on the severity of the B-deficiency condition because plants show uniform deficiency symptoms on entire leaves but sometimes in the form of isolated patches. Given the immobile nature of B, it usually accumulates in mature leaves, whereas young leaves do not receive sufficient B for proper growth. Thus, the deficiency symptoms first appear on young leaves, including thick, curled, and brittle leaves with reduced leaf expansion; corky veins; interveinal chlorosis; yellow water-soaked spots on lamina; and a short internodal distance, resulting in a bushy plant appearance. In severe cases, leaf apex necrosis and leaf dieback occur. To remedy try use some sodium tetraborate mixed with water and apply via foliar application, should notice almost instant remedy in leaves if i am correct in diagnosis. Good luck. 1/4 tsp per litre should suffice to notice.

some are signs of sun/light burn others looks like some kind of deficency (maybe calcium)

If you notice the leaves turning really dark green before suddenly dying off, that could be a sign of nitrogen excess – that's my best guess. For those brown spots, I’d recommend adding some Cal-Mag. Are you keeping an eye on that?

Firstly, too much nitrogen they are verry dark, so reduce it. The plant is also verry stocky, how strong is your lighting? Too much fertilizer + too much light damages your leaves. So just plain water and less light I think Much success 🤞 And Happy Growing