Some of the smaller citrus trees are getting some yellowed leaves like mine frequently do in winter with rains. I've added some soil sulfur and a Gro-Power humic acid product. I'm hoping that along with less rain will help fix this. Only the citrus trees got the sulfer, but all fruit trees got Gro-Power.
I recall that several homes ago, my citrus would get similar issues. Gro-Power and sometimes a foliar spray of seaweed emulsion would help. I don't have any seaweed emulsion at the moment, so hopefully this will help.