The Plant has gotten worse. The head leaves are lo...

Along with what spinnergrow pointed out it looks to me like you have a cal-mag deficiency as well. for whatever reason when grown under LEDS cannabis uses more cal-mag than usual. You can get this from Epson salts or from a cal-mag supplement like calimagik.

Bad Genetics look at your Mutation on your leaves nothing u can do about it 3rd and 4th pic explains your problem just let it grow out and 7 weeks full spectrum 100%%%👍👍✌️✌️

Hello ! Well if your temps are really 17°C during the daytime and 14°C during the night then yes you have a low temperatures issue which lead to a slow grow , the best temps for day time are between 21°C and 27°C for daytime and nightime you should not be under 15°C ( 1°C is not really a big gap but if temps get lower then you will have issues). Now your leaves looks like a Boron deficiency to me and also broad mites like you already been told , if the broad mites diagnosis is confirmed then go there 👉 https://www.growweedeasy.com/cannabis-broad-mites 👈 this article is complete : neem oil seems to be the more efficient/cheaper method. And last thing , at that stage you really really should stard to feed : Supervit is not enough at that stage , she need veg nutrients. I hope it will help you to handle it 😁👍

One thing i noticed were your day and night temps are a bit low..i hear certain bugs and mildew thrive at those low 60s. Also check out the kis organics cannabis science and cultivation podcast they have a killer episode all on artificial lighting, it was a big help understanding the science behind light and what to look for, par, lumen, intensity etc. Happy growing. Best of luck discovering her quirks, happy growing. ✌️