Rust-like spots on leaves

[alexmed95]

Hi everyone,

I wanted to get your take on what could be the problem/disease affecting my Hamlin Orange tree. As you can see from the pictures, some rust-like spots have appeared on multiple leaves over the past couple of weeks. I am dealing with scales, which I treated with two horticultural oil treatments (End-All), and these marks appeared afterward.

Could it be related to sunburn from the oil, or is it a known infection? How can I get rid of it?

Many thanks.