No, that's always been there. But as you say, nobody ever uses it, because we don't have to.
I'm stumped, sorry. I don't know why this would be happening.
I'm not aware of any setting which controls that. It sounds more like a glitch to me.
Can you click and immediately drag to make a new selection ok? Is that functionality still working?
You'd need to check two things:
1. Can you still tap to deselect with other tools, such as the Marquee Tool?
2. When you use your mouse, can you click to deselect with the Patch Tool?
Yes, that's right, it's supposed to. Then you invert the mask and paint on the sleeve, exactly as you said. When I did it, the numbers were perfect. An exact match for the jacket colour.