Are they having problems with watering?

Yeah, too wet for one thing. Fertilizer composition is another. Cannabis needs also high amount immobile nutrients especially calcium and magnesium. This is as high as the standard mobile nutrients. My generic proportion is 3N-1P-4K-4Calcium-2Magnesium. Plenty of info in the web regarding mobile and immobile. A quick fix would be spraying Epsum salt for Magnesium. Either egg shell solution, Calcium Nitrate, Ca O for calcium. Immobile is not so easily absorb by root unless pH is right. This is such a hassle. And I rather fix discolor leaves by spray. Good luck

These look overfed. ------------ If plants droop after a watering, it's a poorly constituted substrate. More perlite or similar needed. Simple watering procedure is all you need to follow.... 1) water entire pot 2) wait for minimal dryback that avoids risks of pathogens and such, then repeat. It's that simple. Don't over-complicated it. I'd recommend a more pronounced wet-dry cycle early on and if you want to irrigate more frequently later, that's okay as long as you allow some healthy amount of dry back that avoids root rot and other risks. Coco - allow top layer to change color early on, at least and in soil/sphagnum peat moss let top 1/2-1" dry before repeating. You can safely irrigate sooner, but this will promote more root mass early on if it is seeking out water a bit -- Don't cause wilt, of course. Probably a minimum of 33% loss of weight froma properly constituted substrate is a safe minimum dryback. Believe this is what the do in a frequent 3x/day fertigation schedule. I'd stick to 50% weight loss as minimum if not trying to push the edge... even that is a bit early compared to the suggestion above. Save this for a plant with a root mass to warrant it. Drippers may not be as perfect about fully saturating the pot as hand-watering, but it can be good enough. Make sure it gets wet all the way down and if this is a soilless substrate, ensure 10% of irrigation runs out the bottom. Slight risk of buildup of fertilizer around the edges of what does get wet -- ebb and flow of moisture will deposit unused minerals that could potentially build up. So, the better the drippers are at distributing water throughout entire volume, the better. My irrigation system misses a couple spots on top near edges of pot. Haven't had a problem so far. I actually position the 2 sprinkler drippers slightly on 'high' side. My platform has a 2" sloop over 8' for drainage. So one little sliver of top soil doesn't directly get wet. No biggie as I don't want superficial roots anyway. The top 1.5" or so of my substrate doesn't have roots because i employ good watering habits. Roots should drive downward toward greater moisture, not upward. This is dependent on proper watering habits.

lack of magnesium - yes, your watering regime only you know.