Cal mag or ph burn?

i had to go away for about a month and when I just got home my chem d cookies looks a little messed up. I has someone watching over it but I think this is a new problem.
What exactly does this look like and how should I attempt fixing it?
I'm in veg using advanced nutrients, sensi grow a+b
Thanks

Dam something simular happens to me when I leave a couple plants without light over them for multiple days. We used to call it rust mold. I would defoliate all the messed up leafs and top the plant about right where it looks healthy so you have a new start. Good luck