So far this only occurred with the FastStone Image Viewer. I pinned the FSViewer.exe to the taskbar on my left monitor. When I press it, it opens the program, but the icon doesn't go into an 'open window' state. Instead the open window shows up on my main taskbar on my centre monitor. The image viewer's window is open on the left monitor, yet the pinned icon on the left taskbar doesn't show it as open.

Taskbar mode is on "all taskbars show relevant windows". It works fine for all other programs, just this particular application doesn't show the open window on the correct taskbar.

Hi, I'm also having this problem specifically with FastStone Image Viewer. Using the 'relevent windows' setting, it's very inconsistent when I have the window on my second monitor. Sometimes showing as active on my primary taskbar, sometimes on neither. My secondary taskbar never shows the active icon.

Yes, the main window it displays on launch.

Works perfectly, thanks so much