Hello friends, I have some plants in my indoor veg...

Phosphorous deficiency.

Most likely a major nutrient deficiency, since there is no nutrients in the water and the the nutrients in the soil get washed out slowly with every watering. Start feeding them with fertilizer, preferably designed for cannabis. Don’t use the full strength at the beginning, so you don’t shock them. Then watch how they develop.

In soil, during veg i see such leaves if my wet/dry cycle was wrong or humidity spike and bad air circulation in very dense canopy , ussually its tent brushing leaves ... In flower - lack of phosphorus and maybe i see small lack of calcium. Thats most common mistakes that i did and had same looking leaves.

How have u been feeding them in the past, has the pH been in the proper range the whole time? What growing medium? Root zone temperature? Looks kinda like phosphorus deficiency.