Help, lower leaves yellowing/browning slightly

Just transplanted these girls this past saturday from 1 gallon containers to their final bags. They're growing well, but some have yellowing/browning on the first true leaves (lowest besides cotyledons.) Outdoor container grow. Using fox farms soil and nutes, been feeding them with big bloom and grow big on the recommended schedule. Possibly too much or not enough nutrients? This is my first time growing, a little worried. This is happening to 3 of my 12 plants, and I'm feeding them all the same. Pictures attached. Any help is appreciated.

Your plants look really good I wouldnt let it bother you too much they arent even true leaves. Doesnt look to be nute burn id just keep up what youre doing good work