I’ve attached a blendfile with two objects, both with weird behaviour in the UV editor with proportional editing on:
Object 1: Hit tab to go into edit mode, G to move in the UV editor and you’ll see another vert moves along with it. Proportional size is set very small, moves even if you scroll down to zero.
Object 2: All verts move when you try to move just one.
Weirdly, if i append those two objects into a new blendfile the UV editor works as expected.
UV_Proportional_Bug.blend (1.3 MB)
EDIT: Appending the Scene into a new blendfile results in the same weird behaviour…