Yellowing new leaves maybe only since flipping

Plants tend to uptake a lot more nitrogen and magnesium in the first 3 weeks since going to a 12/12. If that was me I would raise the amount of base nutrient a touch and add about 0.7 to 1ml cal/mag per L. I zoomed in on the leaves a a couple look like they are lightening up in between the veins which is a sign of mg deficiency. Happy growing pal, nothing to worry about and a easy fix👍

Not seeing anything out of the ordinary, new rapid growth takes a bit longer to green up than the rest as iron moves into the new growth to set up chlorophyll production. If the leaves don't green out in a few days, then I'd start looking in micronutrient/immobile nutrient deficiencies, but I don't think you have anything to worry about. Feel free to send me a DM if you have any questions! Good luck!