The second one

nothing serious can mean flowering is starting. but if this continues even when the leave grows bigger we'll then will be iron deficiency you will need to flush and check if your PH meter work correctly

Flush the soil for one time with water with the right pH and low amount of nutrients with the right NPK ratio and use 2 times the pot volume in water. Let the soil dry for 2-3 days and after continue watering like you are used to with water and nutrients. Again make sure that you are using the right NPK ratio for every phase of the grow. And occasionally give water till runoff to prevent salt buildup in the soil.