You cannot drag files onto it to open in other programs or copy/move them, last I checked. This is a showstopper for my workflow. I just want to drag a file over my explorer icon, choose the window from the popup preview that I want to move it to, have the window get focus, and drop it in the window to move it. Or drag a file over a program icon, have the program get focus, and drop the file on it to open it. Apparently, that is too difficult to port from every previous version of Windows into v11. It sucks.
Does the preview not open up? I run Windows 11 but I'm so old school that I don't group taskbar buttons and you drag a file to the taskbar it will bring the app into focus and I drop it on that app.
But I noticed that I don't get the preview when dragging over the button but that might also have something to do with my particular setup.
I just made a very cursory look into this, but this is possibly that a Group Policy default that has changed to a different setting in Windows 11 than it had been in previous versions of Windows.
It absolutely does work if you disable UAC via Group Policy, but disabling UAC in my opinion is much a step too far as that loosens security in too many areas and would greatly increase Windows 11's attack surface.
I'll open an issue to investigate trying to identify the Group Policy setting to change to specifically re-enable this behavior without disabling UAC. Be advised that it'll be a few weeks as I'll be waiting until the January patch to drop (should be January 9th, 2024) for me to test prior to the January 2024 update to the guide.