Ficus new shots turning yellow ish with brown/black spots

Hello. I deoliated my ficus for 2 months ago, many shoots came back and it is in full leaf now. I had an attack by alphids for 3 weeks ago but got rid of them with water jet and a spray against them.

Its potted in two parts akadama, one part pumice, one part lava rock and 1/2 part moss i found outside and chopped.

Lately my ficus has started getting yellow colour on leafs. Ser picture, i suspect it is some fungi or mold?.

Uploading: E28085AC-9610-475E-8C56-7E67FD954F72.jpeg… Uploading: 7681A8AD-1137-4833-B705-33928E7F93AC.jpeg…