Any advise is always welcome!

Feed via the roots vs the leave. much better efficiency. you appear to have a light meter on a stick in your photos. IDK if it gives this to you in Lux Or something else but you should all the information at your fingertips right there. 18/6 is more then enough with most lights anying over eg, 20/4 and 24/0 are waste of electricity. Look up and familiarize yourself with DLI. Its gold standard for how much like you need. 35-40 is good.

Everything goes well Slightly increase the light 35000-40000 LUX after 7 days - increase 40000-44000 LUX Increase fertilizers 600 - 650 PPM - standart base fertilizer after 7 days - increase 650-700 ppm

He,d listened to m0use xD Let,s see how this goes😅

5g/liter would be a shit ton... hope it's fine or a type-o. 5g/gal is ... 129 / 170 mg/s, respectively. x3.79 l/g = 489 ppm mg and 644ppm S. In a soiless/hydro context this is 6.5x too much Mg and S feeding through roots and you are suppose dto give much less in a foliar feed. That is a veritable shit-ton for foliar feed. If oyu see problem in the coming days, probably the cause. You should always fix nutrient issues by changing what you feed the plants through the roots. An extreme context may justify foliar sprays, but does not look like the case here. foliar feeding is a way to provide specific nutes to a specific locale, but relying on it is a very bad idea. just going to clog up stomata with minerals, which will reduce transpiration and co2 intake, which is a bigger priority. Plus, wet leaves indoors is a creating a needless disease vector. small issues just take a bit more epsom salt in your normal fertilization and no risks. one tidbit about Mg... when you see symptoms it is 4-6 weeks after the deficiency began. So, in future you may need to add more Mg earlier on than you think. The deficiency started a month or more ago, and that's what you need to preempt - not when you saw the symptoms in the context of Mg. I don't even clearly see any Mg-def symptoms in these pictures... interveinal chlorosis with coinciding spots... foliar feeds should be a last ditch effort or for a very specific context and not a common occurence. It's more for people that need to 'feel' they are doing something or value doing things differently for the sake of being different without any reason to do so. i.e. akin to masturbation. Keep it simple. fix fertilizer formula and move on. Avoid the symptoms next time.