Here is a sample image provided by someone on the DPreview Retouching forum

First, here is a Mask AI result and against a light background the cutout looks ok

But against a dark background it is unusable

With Foreground recovery cranked all the way up you get a better result but still not really usable

You have to switch to Remask AI with its tools to get a usable result

Unfortunately this is true for a lot of the published examples I have seen from Mask AI. Looks fine against a light background but not so much against a dark background. The developers need to provide better tools to deal with these halos.