I agree worth trying ,almost always fixes issues. Imo likely a pH issue.almost always is… But transplanting will surely help with almost any issue at hand.the plants are spaced enough I doubt they are yellowing due to low light. But that is possible some plants are fussy that way.my skunkband is super fussy w low light. Check your substrate pH and transplant those one gal bags are ok for tiny plants only. (Srry often I’m late to the party haha, and I don’t read enough before I respond to not be radundent 
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Trim the bottom inside of the plant . Cannabis can survive with 50% of its leaves. Thin it out and repot in fresh coco