Soft Brush has noise problem

[luckylegion14]

When I switch to a soft brush there is a pixelated noise around the adges (transparent areas) a bit like the dissolve brush mode. The brush is 100% opacity, normal blend mode (as is the layer) and its the defult soft brush. This noise appears on any brush no matter how complex that has transparency or soft effects. Happens between documents and after hard restart. Please see the attatched photo

[c.pfaffenbichler]

Could you please post, not attach, a screenshot with the pertinent Panels (Toolbar, Layers, Brush Settings, Options Bar, …) visible?