The automatic chromatic aberration removal tool doesn't seem to work in 9.3 anymore. Here are two screenshots with the box unchecked and checked: there is no visible effect. Going to the « Manual » tab, and fine tuning the correction works though.
CA can be remarkably tricky to remove. I've had images where nothing I did had any effect. The only "apparent" correlation is sensor size. I've found it much more difficult to remove from very small sensors such as 2/3" or smaller, even a few M43 images had to go into the bit bucket. Of course it is much worse for jpegs than raws for any size sensor.