This has happened for a long time, thought I'd mention it...
I have 2 monitors and Windows 10. I have the Windows taskbar enabled on both monitors.
Say I open Power BI, and move it to my secondary monitor, and maximize it. Then, say I close Power BI. Now, if I open Power BI again, Windows "remembers" that Power BI should be opened on my secondary monitor, and that is where it appears. However, Power BI's taskbar icon is back over in the primary monitor's taskbar!
If I move the Power BI app to the primary monitor, then back to the secondary monitor, "fixes" it -- now, the app window is on the secondary monitor, and the taskbar icon moves to the secondary monitor.
I've never seen any other app behave this way, but Power BI does it consistently. It's weird. Can you fix it? Thanks!