1st thing to do whenever you see issues pop up is always double check you are watering with a proper ph level in your water.
If you are doing so then my next suggestion would be to look at how often you are watering them. Overwatering can cause all sorts of issues. I always recommend watering by weight. Lift the pot when fully watered and every day after until the pot feels light. When the pot is very light then it is time to water.
If overwatering isn't the issue then double check your feeding schedule(I've messed up here before). Make sure you are feeding the proper amount of nutes for this stage in the plant's life based on the brand you are using. Depending on the brand of the nutes it might be a good idea to slowly raise the nutes up to the recommended level.
With soil feeding, nutes is a bit different as many soils have enough nutes in them to last the plant about 3-4 weeks without transplanting. If you transplant you can usually add another 3-4 weeks of not needing nutes. I believe this may be your issue. You only have power roots listed as what you are feeding it. That is a very low concentration nutrient that is mostly geared towards good root growth. I think you should either transplant up to the next pot size if you planned on doing so, or start feeding your veg nutes. Specifically, it looks nitrogen and calcium deficient. If you are watering with filtered water you may need to add additional calcium via a calmag supplement or an amendment if your base nutes don't correct the issue.