Simple reproduction of the problem. Create a window, specify:

<Window.TaskbarItemInfo> <TaskbarItemInfo ProgressState="Indeterminate"/> </Window.TaskbarItemInfo>

We start in Windows7 - nothing is displayed on the panel.

We start in Windows10 - on the panel the expected running status bar.

    1 answer 1

    Suddenly and unexpectedly - turning off and turning on the setting helped: enter image description here