Masking changes with new update

I am wondering if anyone is struggling with masking ever since the new updates to lightroom? On both lr app on desktop and my mobile phone, masking seems to not be as accurate as it was before the update. I do product photography and so I use masking to get bright white backgrounds but also to edit the shadows of objects. Previously, I could sample the grey of a shadow and using the refine slider let me choose the shadows I want to adjust very specifically. Now, it seems that when I choose a grey shadow, there are also other colors in the mask, and refining it doesn't help because it also unmasks the shadows that I need to edit. It also seems to be selecting a larger range of colors when I am choosing white as the sample color for a mask and it is also adjusting blue/light blue objects in the photo. It was not doing this before the update! But this is what I do for a living and I need it fixed! Please help!