'busy' QProgressBar problems with style sheet

[elkvis]

it seems when I add a style sheet to a QProgressBar or the object that contains it, the busy (min 0, max 0) progress bar no longer shows any animation. it is just fixed at the left side of the progress bar, and does not move. it makes no difference if I specifically style the progress bar itself, or any of the controls in the container. is this a known issue? is there a workaround for it? or is there just a proper way to do this that I'm not seeing?

[elkvis]

does anyone know what's going on here? I'd like to style a window that contains a busy progress bar, but I cannot because the bar does not animate if there is a style sheet applied to any control in the window.

can someone try to help me with this?